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Sample records for line flux upper

  1. Rapid reconnection of flux lines

    Samain, A.

    1982-01-01

    The rapid reconnection of flux lines in an incompressible fluid through a singular layer of the current density is discussed. It is shown that the liberated magnetic energy must partially appear in the form of plasma kinetic energy. A laminar structure of the flow is possible, but Alfven velocity must be achieved in eddies of growing size at the ends of the layer. The gross structure of the flow and the magnetic configuration may be obtained from variational principles. (author)

  2. Flux qubit to a transmission line

    Haeberlein, Max; Baust, Alexander; Zhong, Ling; Gross, Rudolf [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Physik-Department, TU Muenchen, Garching (Germany); Nanosystems Initiative Munich (NIM), Muenchen (Germany); Anderson, Gustav; Wang, Lujun; Eder, Peter; Fischer, Michael; Goetz, Jan; Xie, Edwar; Schwarz, Manuel; Wulschner, Karl Friedrich; Deppe, Frank; Fedorov, Kirill; Huebl, Hans; Menzel, Edwin [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Physik-Department, TU Muenchen, Garching (Germany); Marx, Achim [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany)

    2015-07-01

    Within the last decade, superconducting qubits coupled to microwave resonators have been extensively studied within the framework of quantum electrodynamics. Ultimately, quantum computing seems within reach in such architectures. However, error correction schemes are necessary to achieve the required fidelity in multi-qubit operations, drastically increasing the number of qubits involved. In this work, we couple a flux qubit to a transmission line where it interacts with itinerant microwave photons granting access to all-optical quantum computing. In this approach, travelling photons generate entanglement between two waveguides, containing the qubit information. In this presentation, we show experimental data on flux qubits coupled to transmission lines. Furthermore, we will discuss entanglement generation between two separate paths.

  3. Statistical mechanics of flux lines in high-temperature superconductors

    Dasgupta, C.

    1992-01-01

    The shortness of the low temperature coherence lengths of high T c materials leads to new mechanisms of pinning of flux lines. Lattice periodic modulations of the order parameters itself acts to pin vortex lines in regions of the unit cell were the order parameter is small. A presentation of flux creep and flux noise at low temperature and magnetic fields in terms of motion of simple metastable defects on flux lines is made, with a calculation of flux lattice melting. 12 refs

  4. The microscopic investigation of structures of moving flux lines by ...

    Abstract. We have used a variety of microscopic techniques to reveal the structure and motion of flux line arrangements, when the flux lines in low Tc type II superconductors are caused to move by a transport current. Using small-angle neutron scattering by the flux line lattice (FLL), we are able to demonstrate directly the ...

  5. Thermal problems on high flux beam lines

    Avery, R.T.

    1983-09-01

    Wiggler and undulator magnets can provide very intense photon flux densities to beam line components. This paper addresses some thermal/materials consequences due to such impingement. The LBL/Exxon/SSRL hybrid-wiggler Beam Line VI now nearing operation will be able to provide up to approx. 7 kW of total photon power at planned SPEAR operating conditions. The first masks are located at 6.5 meters from the source and may receive a peak power density (transverse to the beam) exceeding 20 kW/cm 2 . Significantly, this heat transfer rate exceeds that radiated from the sun's surface (7 kW/cm 2 ) and is comparable to that of welding torches. Clearing, cooling and configuration are of critical importance. Configurations for the first fixed mask, the movable mask, and the pivot mask on this beam line are presented together with considerations of thermal stress fatigue and of heat transfer by conduction to water-cooling circuits. Some preliminary information on heating of crystals and mirrors is also presented

  6. Neutron-diffraction investigations of flux-lines in superconductors

    Forgan, E M [Birmingham Univ. (United Kingdom); Lee, S L [Saint Andrews Univ. (United Kingdom); McKPaul, D [Warwick Univ., Coventry (United Kingdom); Mook, H A [Oak Ridge National Lab., TN (United States); Cubitt, R [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)

    1997-04-01

    SANS has proved an extremely useful tool for investigating flux-line structures within the bulk of superconductors. With high-T{sub c} materials, the scattered intensities are weak, but careful measurements are giving important new information about flux lattices, flux pinning and flux-lattice melting. (author). 10 refs.

  7. Sensitivity of upper atmospheric emissions calculations to solar/stellar UV flux

    Barthelemy Mathieu

    2014-01-01

    Full Text Available The solar UV (UltraViolet flux, especially the EUV (Extreme UltraViolet and FUV (Far UltraViolet components, is one of the main energetic inputs for planetary upper atmospheres. It drives various processes such as ionization, or dissociation which give rise to upper atmospheric emissions, especially in the UV and visible. These emissions are one of the main ways to investigate the upper atmospheres of planets. However, the uncertainties in the flux measurement or modeling can lead to biased estimates of fundamental atmospheric parameters, such as concentrations or temperatures in the atmospheres. We explore the various problems that can be identified regarding the uncertainties in solar/stellar UV flux by considering three examples. The worst case appears when the solar reflection component is dominant in the recorded spectrum as is seen for outer solar system measurements from HST (Hubble Space Telescope. We also show that the estimation of some particular line parameters (intensity and shape, especially Lyman α, is crucial, and that both total intensity and line profile are useful. In the case of exoplanets, the problem is quite critical since the UV flux of their parent stars is often very poorly known.

  8. Weak point disorder in strongly fluctuating flux-line liquids

    We consider the effect of weak uncorrelated quenched disorder (point defects) on a strongly fluctuating flux-line liquid. We use a hydrodynamic model which is based on mapping the flux-line system onto a quantum liquid of relativistic charged bosons in 2 + 1 dimensions [P Benetatos and M C Marchetti, Phys. Rev. B64 ...

  9. Flux-line-cutting losses in type-II superconductors

    Clem, J.R.

    1982-01-01

    Energy dissipation associated with flux-line cutting (intersection and cross-joining of adjacent nonparallel vortices) is considered theoretically. The flux-line-cutting contribution to the dissipation per unit volume, arising from mutual annihilation of transverse magnetic flux, is identified as J/sub parallel/xE/sub parallel/, where J/sub parallel/ and E/sub parallel/ are the components of the current density and the electric field parallel to the magnetic induction. The dynamical behavior of the magnetic structure at the flux-line-cutting threshold is shown to be governed by a special critical-state model similar to that proposed by previous authors. The resulting flux-line-cutting critical-state model, characterized in planar geometry by a parallel critical current density J/sub c/parallel or a critical angle gradient k/sub c/, is used to calculate predicted hysteretic ac flux-line-cutting losses in type-II superconductors in which the flux pinning is weak. The relation of the theory to previous experiments is discussed

  10. Quantum depinning of flux lines from columnar defects

    Chudnovsky, E.M.; Ferrera, A.; Vilenkin, A.

    1995-01-01

    The depinning of a flux line from a columnar defect is studied within the path-integral approach. Instantons of the quantum field theory in 1+1 dimensions are computed for the flux line whose dynamics is dominated by the Magnus force. The universal temperature dependence of the decay rate in the proximity of the critical current is obtained. This problem provides an example of macroscopic quantum tunneling, which is accessible to the direct comparison between theory and experiment

  11. Flux Cloning in Josephson Transmission Lines

    Gulevich, D.R.; Kusmartsev, F.V.

    2006-01-01

    We describe a novel effect related to the controlled birth of a single Josephson vortex. In this phenomenon, the vortex is created in a Josephson transmission line at a T-shaped junction. The 'baby' vortex arises at the moment when a 'mother' vortex propagating in the adjacent transmission line passes the T-shaped junction. In order to give birth to a new vortex, the mother vortex must have enough kinetic energy. Its motion can also be supported by an externally applied driving current. We determine the critical velocity and the critical driving current for the creation of the baby vortices and briefly discuss the potential applications of the found effect

  12. Line width of Josephson flux flow oscillators

    Koshelets, V.P.; Dmitriev, P.N.; Sobolev, A.S.

    2002-01-01

    to be proven before one initiates real FFO applications. To achieve this goal a comprehensive set of line width measurements of the FFO operating in different regimes has been performed. FFOs with tapered shape have been successfully implemented in order to avoid the superfine resonant structure with voltage...... spacing of about 20 nV and extremely low differential resistance, recently observed in the IVC of the standard rectangular geometry. The obtained results have been compared with existing theories and FFO models in order to understand and possibly eliminate excess noise in the FFO. The intrinsic line width...

  13. Flux line lattice in type II super conductors

    Manindra Kumar; Singh, Arun Kumar; Surendra Kumar

    2003-01-01

    The shear modules C 66 of the flux line lattice in type II super conductors can be obtained from a two body interaction between the flux lines even at large inductions B ∼ HC 2 . The potential is composed of a repulsive and an attractive part and has a range diverging at HC 2 . An explicit expression for the Ginzberg-Landau C 66 is given for arbitrary B and k' (G-L parameter). The graph for C 66 exhibits the expected maximum at a certain value of b. (author)

  14. Flux-line cutting in granular high-temperature superconductors

    Perez-Rodriguez, F.; Perez-Gonzalez, A.; Clem, J.R.; Gandolfini, G.; LeBlanc, M.A.

    1997-01-01

    The magnetic response of granular high-temperature superconducting plates subjected to a dc-bias magnetic field and an increasing field perpendicular to it is studied both experimentally and theoretically. The theoretical model is based upon the double critical-state model, which considers not only flux transport but also flux-line cutting effects. Curves of magnetization for the system of grains decoupled by the applied magnetic field in sintered slabs of YBa 2 Cu 3 O 7-x and NdBa 2 Cu 3 O 7-x are analyzed. Good agreement between experimental results and theory is obtained. copyright 1997 The American Physical Society

  15. Thermal bifurcation in the upper solar photosphere inferred from heterodyne spectroscopy of OH rotational lines

    Deming, D.; Hillman, J. J.; Kostiuk, T.; Mumma, M. J.; Zipoy, D. M.

    1984-01-01

    Low noise high spectral resolution observations of two pure rotation transitions of OH from the solar photosphere were obtained. The observations were obtained using the technique of optically null-balanced infrared heterodyne spectroscopy, and consist of center-to-limb line profiles of a v=1 and a v=0 transition near 12 microns. These lines should be formed in local thermodynamic equilibrium (LTE), and are diagnostics of the thermal structure of the upper photosphere. The v=0 R22 (24.5)e line strengthens at the solar limb, in contradiction to the predictions of current one dimensional photospheric models. Data for this line support a two dimensional model in which horizontal thermal fluctuations of order + or - 800K occur in the region Tau (sub 5000) approximately .001 to .01. This thermal bifurcation may be maintained by the presence of magnetic flux tubes, and may be related to the solar limb extensions observed in the 30 to 200 micron region.

  16. Thermal bifurcation in the upper photosphere inferred from heterodyne spectroscopy of OH rotational lines

    Deming, D.; Kostiuk, T.; Mumma, M. J.; Hillman, J. J.; Zipoy, D. M.

    1984-01-01

    Low-noise (S/N greater than 100), high spectral resolution observations of two pure rotation transitions of OH from the solar photosphere are used to make inferences concerning the thermal structure and inhomogeneity of the upper photosphere. It is found that the v = O R22(24.5)e line strengthens at the solar limb, in contradiction to the predictions of current one-dimensional photospheric models. The results for this line support a two-dimensional model in which horizontal thermal fluctuations in the upper photosphere are of the order plus or minus 800 K. This thermal bifurcation may be maintained by the presence of magnetic flux tubes and may be related to the solar limb extensions observed in the 30-200-micron region.

  17. SN 1987A gamma-ray line profiles and fluxes

    Bussard, R.W.; Burrows, A.; The, L.S.

    1989-01-01

    Results for the time dependence of the line profiles and integrated fluxes for the 0.847 and 1.238 MeV gamma rays from the decay of cobalt to excited states of iron are presented for several models of the ejectum of SN 1987A. The relatively early detection of these lines has led several workers to propose that some degree of mixing has brought the cobalt closer to the electron-scattering photosphere than standard models predict. Constraints on the amount of mixing from recent observations are discussed using calculations of the energy-integrated line fluxes as a function of time since the explosion. Implications for the line profiles at various times are considered, and it is found that they show strong time dependences and are quite sensitive to the degree of mixing. The two primary effects are Doppler broadening due to the presence of radioactive material at higher velocities and a strong blueshift at early times resulting from optical depth effects. These results have important implications for gamma-ray observations, especially with high-resolution germanium instruments. Finally, the consequences of the fragmentation of the debris for the early emergence of the gamma-ray lines are considered. 32 refs

  18. The upper limit of the solar antineutrino flux according to the LSD array data

    Al'etta, M.; Antonioli, P.; Badino, D.

    1997-01-01

    The analysis of the experimental data obtained at the LSD liquid scintillation detector is carried out with the aim of searching the possible flux of electron antineutrinos from Sun. The most strong at present upper limit for the electron antineutrino flux of solar origin is determined: ≤ 1.0 x 10 5 cm -2 x s -1 (the reliability level of 90%)

  19. Solving the critical state using flux line properties

    Campbell, A M

    2014-01-01

    A method of solving the critical state in superconductors using the vector potential and commercial software (FlexPDE) is described. It avoids both time dependence and power law resistivity. It uses a material parameter which describes how far flux lines move before most become unpinned. This allows small oscillations and minor hysteresis loops to be modelled. The theory is applied to the problem of demagnetisation in bulks due to crossed fields. It may explain why experimental results do not agree with theory. The theory can be extended to coils, and two and three dimensions. This requires the introduction of a scalar potential V o . This is not the usual scalar potential, which is due to electrostatic charges as the field is run up, but the integral of this value at the final field after charges have dissipated. (paper)

  20. Transmission line analogy for relativistic Poynting-flux jets

    Lovelace, R. V. E.; Kronberg, P. P.

    2013-04-01

    Radio emission, polarization and Faraday rotation maps of the radio jet of the galaxy 3C 303 have shown that one knot of this jet carries a galactic-scale electric current and that it is magnetically dominated. We develop the theory of magnetically dominated or Poynting-flux jets by making an analogy of a Poynting jet with a transmission line or waveguide carrying a net current and having a potential drop across it (from the jet's axis to its radius) and a definite impedance which we derive. The electromagnetic energy flow in the jet is the jet impedance times the square of the jet current. The observed current in 3C 303 can be used to calculate the electromagnetic energy flow in this magnetically dominated jet. Time dependent but not necessarily small perturbations of a Poynting-flux jet are described by the `telegrapher's equations'. These predict the propagation speed of disturbances and the effective wave impedance for forward and backward propagating wave components. A localized disturbance of a Poynting jet gives rise to localized dissipation in the jet which may explain the enhanced synchrotron radiation in the knots of the 3C 303 jet, and also in the apparently stationary knot HST-1 in the jet near the nucleus of the nearby galaxy M87. For a relativistic Poynting jet on parsec scales, the reflected voltage wave from an inductive termination or load can lead to a backward propagating wave which breaks down the magnetic insulation of the jet giving |{boldsymbol E}| /|{boldsymbol B}|ge 1. At the threshold for breakdown, |{boldsymbol E}|/|{boldsymbol B}|=1, positive and negative particles are directly accelerated in the {boldsymbol E} × {boldsymbol B} direction which is approximately along the jet axis. Acceleration can occur up to Lorentz factors ˜107. This particle acceleration mechanism is distinct from that in shock waves and that in magnetic field reconnection.

  1. Metabolite Depletion Affects Flux Profiling of Cell Lines

    Nilsson, A.; Haanstra, J. R.; Teusink, B.

    2018-01-01

    Quantifying the rate of consumption and release of metabolites (i.e., flux profiling) has become integral to the study of cancer. The fluxes as well as the growth of the cells may be affected by metabolite depletion during cultivation.......Quantifying the rate of consumption and release of metabolites (i.e., flux profiling) has become integral to the study of cancer. The fluxes as well as the growth of the cells may be affected by metabolite depletion during cultivation....

  2. The dynamic history of the upper forest line ecotone in the northern Andes

    Hooghiemstra, H.; Berrio, J.C.; Groot, M.H.M.; Bogotá-A, R.G.; Moscol Olivera, M.; González-Carranza, Z.; Myster, R.W.

    2012-01-01

    In the Andean cordilleras very conspicuous ecotones can be found. The transition from continuous upper montane forest to treeless herbaceous vegetation, regionally known as "páramo" (Cleef 1981; Luteyn 1999) is known as the "upper forest line" (UFL) or "timber line" (Holtmeier 2009). Above the UFL

  3. On the inversion problem of the plasma line intensity measurements in terms of photoelectron fluxes

    Lejeune, G.

    1979-01-01

    Assuming that the unidimensional distribution function of the photoelectron flux can be determined from plasma line intensity measurement, it is shown that the photoelectron flux distribution is not uniquely determined if additional hypotheses are not made. The limitations of the inversion procedure are shown: in particular, plasma line measurements cannot allow the determination of more than the first two Legendre components of the photoelectron flux. Experimental procedures for this determination are finally reviewed. (author)

  4. Flux line patterns in Bi2Sr2Ca1Cu2Ox

    Weiss, F.; Hardy, V.; Provost, J.; Ruyter, A.; Simon, C.

    1994-01-01

    Results of the defect influence on the flux line lattice in Bi 2 Sr 2 Ca 1 Cu 2 O x single crystals are presented. These crystals, non irradiated or irradiated at GANIL with heavy ions (Pb 56+ , 6 GeV) have been decorated with Ni particles in the superconducting state using the Bitter technique. The defects involved are columnar defects. Resulting decorated flux line patterns have been characterized using scanning electron microscopy and computer image analysis. Disorder of the decorated flux line networks has been found to be strongly dependent on the defect density, which results from the irradiation. In order to characterize this disorder, a method for determining elastic energy terms in the deformation of flux line patterns has been investigated. This method can be applied if Fourier transforms of the decorated flux line patterns exhibit distinct reflections. (orig.)

  5. Experimental observation on asymmetric energy flux within the forbidden frequency band in the LC transmission line

    Tao Feng; Chen Weizhong; Pan Junting; Xu Wen; Du Sidan

    2012-01-01

    We study the energy flux in a nonlinear electrical transmission line consisting of two coupled segments which are identical in structure and different in parameters. The asymmetry of energy flux caused by nonlinear wave has been observed experimentally in the forbidden band of the line. The experiment shows whether the energy can flow through the transmission line depends on the amplitude of the boundary driving voltages, which can be well explained in the theoretical framework of nonlinear supratransmission. The numerical simulation based on Kirchhoff’s laws further verifies the existence of the asymmetric energy flux in the forbidden band.

  6. An Improved Seeding Algorithm of Magnetic Flux Lines Based on Data in 3D Space

    Jia Zhong

    2015-05-01

    Full Text Available This paper will propose an approach to increase the accuracy and efficiency of seeding algorithms of magnetic flux lines in magnetic field visualization. To obtain accurate and reliable visualization results, the density of the magnetic flux lines should map the magnetic induction intensity, and seed points should determine the density of the magnetic flux lines. However, the traditional seeding algorithm, which is a statistical algorithm based on data, will produce errors when computing magnetic flux through subdivision of the plane. To achieve higher accuracy, more subdivisions should be made, which will reduce efficiency. This paper analyzes the errors made when the traditional seeding algorithm is used and gives an improved algorithm. It then validates the accuracy and efficiency of the improved algorithm by comparing the results of the two algorithms with results from the equivalent magnetic flux algorithm.

  7. Orientation-dependent forces between flux lines and crystal lattice in pure niobium

    Holzhauser, W.

    1976-01-01

    Torque measurements were performed with cylindrical niobium crystals, due to the very small pinning of the high-purity material. A torque that tries to align the flux lines along special directions of the crystal lattice was studied

  8. On Line Neutron Flux Mapping in Fuel Coolant Channels of a Research Reactor

    Barbot, Loic; Domergue, Christophe; Villard, Jean-Francois; Destouches, Christophe; Braoudakis, George; Wassink, David; Sinclair, Bradley; Osborn, John-C.; Wu, Huayou; Blandin, C.; Thevenin, Mathieu; Corre, Gwenole; Normand, Stephane

    2013-06-01

    This work deals with the on-line neutron flux mapping of the OPAL research reactor. A specific irradiation device has been set up to investigate fuel coolant channels using subminiature fission chambers to get thermal neutron flux profiles. Experimental results are compared to first neutronic calculations and show good agreement (C/E ∼0.97). (authors)

  9. Study of parameters of simultaneous lasing on two lines sharing an upper level

    Pikulev, A A

    2002-01-01

    Stationary lasing at two competing lines sharing an upper level is studied. Based on the expressions for the gain obtained earlier, the possible lasing regimes are considered (at one or two lines) and approximate formulas are derived for determining the output power in each line. These formulas are shown to be the generalisation of the Rigrod formula to the case of simultaneous lasing at several lines. (control of laser radiation parameters)

  10. SUSPENDED AND DISSOLVED MATTER FLUXES IN THE UPPER SELENGA RIVER BASIN

    Sergey Chalov

    2012-01-01

    Full Text Available We synthesized recent field-based estimates of the dissolved ions (K+ Na+ Ca2+ Mg2+ Cl- SO42- HCO3-, biogens (NO3-, NO2-, PO43-(C, mg/l, heavy metal (Fesum, Mn, Pb and dissolved load (DL, kg/day, as far as suspended sediment concentration (SSC, mg/l and suspended load (SL, kg/day along upper Selenga river and its tributaries based on literature review and preliminary results of our 2011 field campaign. The crucial task of this paper is to provide full review of Russian, Mongolian and English-language literature which concern the matter fluxes in the upper part of Selenga river (within Mongolia. The exist estimates are compared with locations of 3 main matter sources within basin: mining and industry, river-bank erosion and slope wash. The heaviest increase of suspended and dissolved matter transport is indicated along Tuul-Orkhon river system (right tributary of the Selenga River where Mongolia capital Ulanbaatar, gold mine Zaamar and few other mines are located. In measurement campaigns conducted in 2005, 2006 and 2008 the increase directly after the Zaamar mining site was between 167 to 383 kg/day for Fe, between 15 and 5260 kg/day for Mn. Our field campaign indicated increase of suspended load along Tuul river from 4280 kg/day at the upstream point to 712000 kg/day below Ulaanbaatar and Zaamar. The results provide evidence on a potential connection between increased dissolved and suspended matter fluxes in transboundary rivers and zones of matter supply at industrial and mining centers, along eroded river banks and pastured lands. The gaps in the understanding of matter load fluxes within this basin are discussed with regards to determining further goals of hydrological and geochemical surveys.

  11. Upper limit on the diffuse flux of ultrahigh energy tau neutrinos from the Pierre Auger Observatory.

    Abraham, J; Abreu, P; Aglietta, M; Aguirre, C; Allard, D; Allekotte, I; Allen, J; Allison, P; Alvarez-Muñiz, J; Ambrosio, M; Anchordoqui, L; Andringa, S; Anzalone, A; Aramo, C; Argirò, S; Arisaka, K; Armengaud, E; Arneodo, F; Arqueros, F; Asch, T; Asorey, H; Assis, P; Atulugama, B S; Aublin, J; Ave, M; Avila, G; Bäcker, T; Badagnani, D; Barbosa, A F; Barnhill, D; Barroso, S L C; Bauleo, P; Beatty, J J; Beau, T; Becker, B R; Becker, K H; Bellido, J A; BenZvi, S; Berat, C; Bergmann, T; Bernardini, P; Bertou, X; Biermann, P L; Billoir, P; Blanch-Bigas, O; Blanco, F; Blasi, P; Bleve, C; Blümer, H; Bohácová, M; Bonifazi, C; Bonino, R; Boratav, M; Brack, J; Brogueira, P; Brown, W C; Buchholz, P; Bueno, A; Burton, R E; Busca, N G; Caballero-Mora, K S; Cai, B; Camin, D V; Caramete, L; Caruso, R; Carvalho, W; Castellina, A; Catalano, O; Cataldi, G; Cazon, L; Cester, R; Chauvin, J; Chiavassa, A; Chinellato, J A; Chou, A; Chye, J; Clark, P D J; Clay, R W; Colombo, E; Conceição, R; Connolly, B; Contreras, F; Coppens, J; Cordier, A; Cotti, U; Coutu, S; Covault, C E; Creusot, A; Criss, A; Cronin, J; Curutiu, A; Dagoret-Campagne, S; Daumiller, K; Dawson, B R; de Almeida, R M; De Donato, C; de Jong, S J; De La Vega, G; de Mello Junior, W J M; de Mello Neto, J R T; DeMitri, I; de Souza, V; del Peral, L; Deligny, O; Della Selva, A; Delle Fratte, C; Dembinski, H; Di Giulio, C; Diaz, J C; Dobrigkeit, C; D'Olivo, J C; Dornic, D; Dorofeev, A; dos Anjos, J C; Dova, M T; D'Urso, D; Dutan, I; DuVernois, M A; Engel, R; Epele, L; Erdmann, M; Escobar, C O; Etchegoyen, A; Facal San Luis, P; Falcke, H; Farrar, G; Fauth, A C; Fazzini, N; Ferrer, F; Ferry, S; Fick, B; Filevich, A; Filipcic, A; Fleck, I; Fonte, R; Fracchiolla, C E; Fulgione, W; García, B; García Gámez, D; Garcia-Pinto, D; Garrido, X; Geenen, H; Gelmini, G; Gemmeke, H; Ghia, P L; Giller, M; Glass, H; Gold, M S; Golup, G; Gomez Albarracin, F; Gómez Berisso, M; Gómez Herrero, R; Gonçalves, P; Gonçalves do Amaral, M; Gonzalez, D; Gonzalez, J G; González, M; Góra, D; Gorgi, A; Gouffon, P; Grassi, V; Grillo, A F; Grunfeld, C; Guardincerri, Y; Guarino, F; Guedes, G P; Gutiérrez, J; Hague, J D; Hamilton, J C; Hansen, P; Harari, D; Harmsma, S; Harton, J L; Haungs, A; Hauschildt, T; Healy, M D; Hebbeker, T; Hebrero, G; Heck, D; Hojvat, C; Holmes, V C; Homola, P; Hörandel, J; Horneffer, A; Horvat, M; Hrabovský, M; Huege, T; Hussain, M; Iarlori, M; Insolia, A; Ionita, F; Italiano, A; Kaducak, M; Kampert, K H; Karova, T; Kégl, B; Keilhauer, B; Kemp, E; Kieckhafer, R M; Klages, H O; Kleifges, M; Kleinfeller, J; Knapik, R; Knapp, J; Koang, D-H; Krieger, A; Krömer, O; Kuempel, D; Kunka, N; Kusenko, A; La Rosa, G; Lachaud, C; Lago, B L; Lebrun, D; Lebrun, P; Lee, J; Leigui de Oliveira, M A; Letessier-Selvon, A; Leuthold, M; Lhenry-Yvon, I; López, R; Lopez Agüera, A; Lozano Bahilo, J; Luna García, R; Maccarone, M C; Macolino, C; Maldera, S; Mancarella, G; Manceñido, M E; Mandat, D; Mantsch, P; Mariazzi, A G; Maris, I C; Marquez Falcon, H R; Martello, D; Martínez, J; Martínez Bravo, O; Mathes, H J; Matthews, J; Matthews, J A J; Matthiae, G; Maurizio, D; Mazur, P O; McCauley, T; McEwen, M; McNeil, R R; Medina, M C; Medina-Tanco, G; Meli, A; Melo, D; Menichetti, E; Menschikov, A; Meurer, Chr; Meyhandan, R; Micheletti, M I; Miele, G; Miller, W; Mollerach, S; Monasor, M; Monnier Ragaigne, D; Montanet, F; Morales, B; Morello, C; Moreno, J C; Morris, C; Mostafá, M; Muller, M A; Mussa, R; Navarra, G; Navarro, J L; Navas, S; Necesal, P; Nellen, L; Newman-Holmes, C; Newton, D; Nguyen Thi, T; Nierstenhoefer, N; Nitz, D; Nosek, D; Nozka, L; Oehlschläger, J; Ohnuki, T; Olinto, A; Olmos-Gilbaja, V M; Ortiz, M; Ortolani, F; Ostapchenko, S; Otero, L; Pacheco, N; Pakk Selmi-Dei, D; Palatka, M; Pallotta, J; Parente, G; Parizot, E; Parlati, S; Pastor, S; Patel, M; Paul, T; Pavlidou, V; Payet, K; Pech, M; Pekala, J; Pelayo, R; Pepe, I M; Perrone, L; Petrera, S; Petrinca, P; Petrov, Y; Pham Ngoc, Diep; Pham Ngoc, Dong; Pham Thi, T N; Pichel, A; Piegaia, R; Pierog, T; Pimenta, M; Pinto, T; Pirronello, V; Pisanti, O; Platino, M; Pochon, J; Privitera, P; Prouza, M; Quel, E J; Rautenberg, J; Redondo, A; Reucroft, S; Revenu, B; Rezende, F A S; Ridky, J; Riggi, S; Risse, M; Rivière, C; Rizi, V; Roberts, M; Robledo, C; Rodriguez, G; Rodríguez Frías, D; Rodriguez Martino, J; Rodriguez Rojo, J; Rodriguez-Cabo, I; Ros, G; Rosado, J; Roth, M; Rouillé-d'Orfeuil, B; Roulet, E; Rovero, A C; Salamida, F; Salazar, H; Salina, G; Sánchez, F; Santander, M; Santo, C E; Santos, E M; Sarazin, F; Sarkar, S; Sato, R; Scherini, V; Schieler, H; Schmidt, A; Schmidt, F; Schmidt, T; Scholten, O; Schovánek, P; Schüssler, F; Sciutto, S J; Scuderi, M; Segreto, A; Semikoz, D; Settimo, M; Shellard, R C; Sidelnik, I; Siffert, B B; Sigl, G; Smetniansky De Grande, N; Smiałkowski, A; Smída, R; Smith, A G K; Smith, B E; Snow, G R; Sokolsky, P; Sommers, P; Sorokin, J; Spinka, H; Squartini, R; Strazzeri, E; Stutz, A; Suarez, F; Suomijärvi, T; Supanitsky, A D; Sutherland, M S; Swain, J; Szadkowski, Z; Takahashi, J; Tamashiro, A; Tamburro, A; Taşcău, O; Tcaciuc, R; Thomas, D; Ticona, R; Tiffenberg, J; Timmermans, C; Tkaczyk, W; Todero Peixoto, C J; Tomé, B; Tonachini, A; Torres, I; Torresi, D; Travnicek, P; Tripathi, A; Tristram, G; Tscherniakhovski, D; Tueros, M; Tunnicliffe, V; Ulrich, R; Unger, M; Urban, M; Valdés Galicia, J F; Valiño, I; Valore, L; van den Berg, A M; van Elewyck, V; Vázquez, R A; Veberic, D; Veiga, A; Velarde, A; Venters, T; Verzi, V; Videla, M; Villaseñor, L; Vorobiov, S; Voyvodic, L; Wahlberg, H; Wainberg, O; Walker, P; Warner, D; Watson, A A; Westerhoff, S; Wieczorek, G; Wiencke, L; Wilczyńska, B; Wilczyński, H; Wileman, C; Winnick, M G; Wu, H; Wundheiler, B; Yamamoto, T; Younk, P; Zas, E; Zavrtanik, D; Zavrtanik, M; Zech, A; Zepeda, A; Ziolkowski, M

    2008-05-30

    The surface detector array of the Pierre Auger Observatory is sensitive to Earth-skimming tau neutrinos that interact in Earth's crust. Tau leptons from nu(tau) charged-current interactions can emerge and decay in the atmosphere to produce a nearly horizontal shower with a significant electromagnetic component. The data collected between 1 January 2004 and 31 August 2007 are used to place an upper limit on the diffuse flux of nu(tau) at EeV energies. Assuming an E(nu)(-2) differential energy spectrum the limit set at 90% C.L. is E(nu)(2)dN(nu)(tau)/dE(nu)<1.3 x 10(-7) GeV cm(-2) s(-1) sr(-1) in the energy range 2 x 10(17) eV< E(nu)< 2 x 10(19) eV.

  12. Upper shelf toughness of six submerged-arc weldmetals manufactured using Linde 124 flux

    Druce, S.G.; Hippsley, C.A.

    1984-06-01

    This paper describes the testing technique, data analysis procedures and results from the first phase of an experimental programme investigating upper shelf toughness of six submerged-arc weldmetals. The welds were manufactured using uncoated, Nickel coated and Copper coated wire electrodes and Linde 124 flux. J integral crack growth resistance curves have been derived from tests on single specimens over a range in temperature from 150 to 290 deg C. The results indicate a general decline in toughness with increasing temperature. At 290 deg C, the levels of initiation toughness from all six welds were essentially constant varying between 152 to 159 MPa square root of m. The Jsub(I)-R curves derived from this work are compared with toughness data used in the Marshall Study Group report of an assessment of the integrity of PWR pressure vessels. (author)

  13. Measurements and calculations of neutron fluxes through a simulation of the CRBR upper axial shielding

    Maerker, R.E.; Muckenthaler, F.J.

    1976-01-01

    Measurements, using a 4-in. Bonner Ball, have been made of the neutron fluxes penetrating a simulation of CRBR upper axial biological shielding at the Tower Shielding Facility. The simulation consisted of a 45.7 cm thick slab of SS-304 followed by a series of sodium tanks having a total thickness of 457 cm followed by slabs of carbon steel up to 61.0 cm thick. Measurements were made behind the stainless steel, behind intermediate thicknesses of 152 cm, 305 cm, and 457 cm of sodium (with the stainless steel in place), and behind various thicknesses of the carbon steel following both 305 cm and 457 cm of sodium (also with the stainless steel in place). Calculated and measured data are presented and compared

  14. Upper limit on the ultrahigh-energy photon flux from AGASA and Yakutsk data

    Rubtsov, G.I.; Dedenko, L.G.; Fedorova, G.F.; Fedunin, E.Yu.; Roganova, T.M.; Glushkov, A.V.; Makarov, I.T.; Pravdin, M.I.; Sleptsov, I.E.; Gorbunov, D.S.; Troitsky, S.V.

    2006-01-01

    We present the interpretation of the muon and scintillation signals of ultrahigh-energy air showers observed by AGASA and Yakutsk extensive air shower array experiments. We consider case-by-case ten highest-energy events with known muon content and conclude that at the 95% confidence level none of them was induced by a primary photon. Taking into account statistical fluctuations and differences in the energy estimation of proton and photon primaries, we derive an upper limit of 36% at a 95% confidence level on the fraction of primary photons in the cosmic-ray flux above 10 20 eV. This result disfavors the Z-burst and superheavy dark-matter solutions to the Greisen-Zatsepin-Kuzmin-cutoff problem

  15. GeV GAMMA-RAY FLUX UPPER LIMITS FROM CLUSTERS OF GALAXIES

    Ackermann, M.; Ajello, M.; Allafort, A.; Bechtol, K.; Blandford, R. D.; Bloom, E. D.; Borgland, A. W.; Bouvier, A.; Buehler, R.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Blasi, P.; Bonamente, E.; Brandt, T. J.; Brigida, M.; Bruel, P.

    2010-01-01

    The detection of diffuse radio emission associated with clusters of galaxies indicates populations of relativistic leptons infusing the intracluster medium (ICM). Those electrons and positrons are either injected into and accelerated directly in the ICM, or produced as secondary pairs by cosmic-ray ions scattering on ambient protons. Radiation mechanisms involving the energetic leptons together with the decay of neutral pions produced by hadronic interactions have the potential to produce abundant GeV photons. Here, we report on the search for GeV emission from clusters of galaxies using data collected by the Large Area Telescope on the Fermi Gamma-ray Space Telescope from 2008 August to 2010 February. Thirty-three galaxy clusters have been selected according to their proximity and high mass, X-ray flux and temperature, and indications of non-thermal activity for this study. We report upper limits on the photon flux in the range 0.2-100 GeV toward a sample of observed clusters (typical values (1-5) x10 -9 photon cm -2 s -1 ) considering both point-like and spatially resolved models for the high-energy emission and discuss how these results constrain the characteristics of energetic leptons and hadrons, and magnetic fields in the ICM. The volume-averaged relativistic-hadron-to-thermal energy density ratio is found to be <5%-10% in several clusters.

  16. A new heat flux model for the Antarctic Peninsula incorporating spatially variable upper crustal radiogenic heat production

    Burton-Johnson, A.; Halpin, J.; Whittaker, J. M.; Graham, F. S.; Watson, S. J.

    2017-12-01

    We present recently published findings (Burton-Johnson et al., 2017) on the variability of Antarctic sub-glacial heat flux and the impact from upper crustal geology. Our new method reveals that the upper crust contributes up to 70% of the Antarctic Peninsula's subglacial heat flux, and that heat flux values are more variable at smaller spatial resolutions than geophysical methods can resolve. Results indicate a higher heat flux on the east and south of the Peninsula (mean 81 mWm-2) where silicic rocks predominate, than on the west and north (mean 67 mWm-2) where volcanic arc and quartzose sediments are dominant. Whilst the data supports the contribution of HPE-enriched granitic rocks to high heat flux values, sedimentary rocks can be of comparative importance dependent on their provenance and petrography. Models of subglacial heat flux must utilize a heterogeneous upper crust with variable radioactive heat production if they are to accurately predict basal conditions of the ice sheet. Our new methodology and dataset facilitate improved numerical model simulations of ice sheet dynamics. The most significant challenge faced remains accurate determination of crustal structure, particularly the depths of the HPE-enriched sedimentary basins and the sub-glacial geology away from exposed outcrops. Continuing research (particularly detailed geophysical interpretation) will better constrain these unknowns and the effect of upper crustal geology on the Antarctic ice sheet. Burton-Johnson, A., Halpin, J.A., Whittaker, J.M., Graham, F.S., and Watson, S.J., 2017, A new heat flux model for the Antarctic Peninsula incorporating spatially variable upper crustal radiogenic heat production: Geophysical Research Letters, v. 44, doi: 10.1002/2017GL073596.

  17. On line local measurement of thermal neutron flux on BNCT patient using SPND

    Miller, M.E.; Sztejnberg Goncalves-Carralves, M.L.; Gonzalez, S.J.

    2006-01-01

    The first on-line neutron flux measurement on a patient using a self-powered neutron detector (SPND) was assessed during the fourth clinical trial of the Boron Neutron Capture Therapy (BNCT) Project carried out at the National Atomic Energy Commission of Argentina (CNEA) and the medical center Angel H. Roffo. The SPND was specially developed and assembled for BNCT by CNEA. Its small size, 1 cm sensible length and 1.9 mm diameter, allowed performing a localized measurement. Since the treated tumors were cutaneous melanomas of nodular type, the SPND was located on the patient's skin. The patient was exposed to three different and consecutive fields and in each of them the SPND was used to measure local thermal neutron fluxes at selected dosimetric reference points. The values of the measured fluxes agreed with the ones estimated by calculation. This trial also demonstrated the usefulness of the SPND for assessing flux on-line. (author)

  18. Quantum tunneling of massive flux lines in a high-T{sub c} superconductor

    Gaber, M.W.; Achar, B.N.N. [Memphis Univ., TN (United States)

    1999-02-01

    We have investigated the quantum tunneling of damped flux lines of finite mass at T = 0 by extending our previous study of tunneling around T{sub 0}, the transition temperature. In the case of a cubic pinning potential, considered here, the action could be evaluated in a closed form for a flux line of finite length. The tunneling rate reaches a finite limit at T = 0, although it is temperature dependent and exhibits a 1/T variation near T{sub 0}. (orig.) 21 refs.

  19. Magnetic flux lines in type-II superconductors and the 'hairy ball' theorem

    Laver, Mark; Forgan, Edward M.

    2010-01-01

    that discontinuities must exist in lattice shape as a function of field direction relative to the crystal. Extraordinary, 'unconventional' flux line lattice shapes that spontaneously break the underlying crystal symmetry are thus remarkably likely across all type-II superconductors, both conventional...

  20. Pinning of a curved flux line by macroscopic inclusions in a type II superconductor

    Shehata, L.N.; Saif, A.G.

    1983-08-01

    The pinning force is calculated as a function of the distance between a curved (or straight) flux line and the centre of a macroscopic superconducting (or normal) ellipsoidal inclusion. When the ellipsoidal tends to a spherical inclusion the results agree with those previously obtained. (author)

  1. Suspended sediment flux modeling with artificial neural network: An example of the Longchuanjiang River in the Upper Yangtze Catchment, China

    Zhu, Yun-Mei; Lu, X. X.; Zhou, Yue

    2007-02-01

    Artificial neural network (ANN) was used to model the monthly suspended sediment flux in the Longchuanjiang River, the Upper Yangtze Catchment, China. The suspended sediment flux was related to the average rainfall, temperature, rainfall intensity and water discharge. It is demonstrated that ANN is capable of modeling the monthly suspended sediment flux with fairly good accuracy when proper variables and their lag effect on the suspended sediment flux are used as inputs. Compared with multiple linear regression and power relation models, ANN can generate a better fit under the same data requirement. In addition, ANN can provide more reasonable predictions for extremely high or low values, because of the distributed information processing system and the nonlinear transformation involved. Compared with the ANNs that use the values of the dependent variable at previous time steps as inputs, the ANNs established in this research with only climate variables have an advantage because it can be used to assess hydrological responses to climate change.

  2. Spectroscopic Diagnostics of Solar Magnetic Flux Ropes Using Iron Forbidden Line

    Cheng, X.; Ding, M. D.

    2016-05-01

    In this Letter, we present Interface Region Imaging Spectrograph Fe xxi 1354.08 Å forbidden line emission of two magnetic flux ropes (MFRs) that caused two fast coronal mass ejections with velocities of ≥1000 km s-1 and strong flares (X1.6 and M6.5) on 2014 September 10 and 2015 June 22, respectively. The extreme-ultraviolet images at the 131 and 94 Å passbands provided by the Atmospheric Imaging Assembly on board Solar Dynamics Observatory reveal that both MFRs initially appear as suspended hot channel-like structures. Interestingly, part of the MFRs is also visible in the Fe xxi 1354.08 forbidden line, even prior to the eruption, e.g., for the SOL2014-09-10 event. However, the line emission is very weak and that only appears at a few locations but not the whole structure of the MFRs. This implies that the MFRs could be comprised of different threads with different temperatures and densities, based on the fact that the formation of the Fe xxi forbidden line requires a critical temperature (˜11.5 MK) and density. Moreover, the line shows a non-thermal broadening and a blueshift in the early phase. It suggests that magnetic reconnection at that time has initiated; it not only heats the MFR and, at the same time, produces a non-thermal broadening of the Fe xxi line but also produces the poloidal flux, leading to the ascension of the MFRs.

  3. SPECTROSCOPIC DIAGNOSTICS OF SOLAR MAGNETIC FLUX ROPES USING IRON FORBIDDEN LINE

    Cheng, X.; Ding, M. D.

    2016-01-01

    In this Letter, we present Interface Region Imaging Spectrograph Fe xxi 1354.08 Å forbidden line emission of two magnetic flux ropes (MFRs) that caused two fast coronal mass ejections with velocities of ≥1000 km s"−"1 and strong flares (X1.6 and M6.5) on 2014 September 10 and 2015 June 22, respectively. The extreme-ultraviolet images at the 131 and 94 Å passbands provided by the Atmospheric Imaging Assembly on board Solar Dynamics Observatory reveal that both MFRs initially appear as suspended hot channel-like structures. Interestingly, part of the MFRs is also visible in the Fe xxi 1354.08 forbidden line, even prior to the eruption, e.g., for the SOL2014-09-10 event. However, the line emission is very weak and that only appears at a few locations but not the whole structure of the MFRs. This implies that the MFRs could be comprised of different threads with different temperatures and densities, based on the fact that the formation of the Fe xxi forbidden line requires a critical temperature (∼11.5 MK) and density. Moreover, the line shows a non-thermal broadening and a blueshift in the early phase. It suggests that magnetic reconnection at that time has initiated; it not only heats the MFR and, at the same time, produces a non-thermal broadening of the Fe xxi line but also produces the poloidal flux, leading to the ascension of the MFRs.

  4. SPECTROSCOPIC DIAGNOSTICS OF SOLAR MAGNETIC FLUX ROPES USING IRON FORBIDDEN LINE

    Cheng, X.; Ding, M. D., E-mail: xincheng@nju.edu.cn [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China)

    2016-05-20

    In this Letter, we present Interface Region Imaging Spectrograph Fe xxi 1354.08 Å forbidden line emission of two magnetic flux ropes (MFRs) that caused two fast coronal mass ejections with velocities of ≥1000 km s{sup −1} and strong flares (X1.6 and M6.5) on 2014 September 10 and 2015 June 22, respectively. The extreme-ultraviolet images at the 131 and 94 Å passbands provided by the Atmospheric Imaging Assembly on board Solar Dynamics Observatory reveal that both MFRs initially appear as suspended hot channel-like structures. Interestingly, part of the MFRs is also visible in the Fe xxi 1354.08 forbidden line, even prior to the eruption, e.g., for the SOL2014-09-10 event. However, the line emission is very weak and that only appears at a few locations but not the whole structure of the MFRs. This implies that the MFRs could be comprised of different threads with different temperatures and densities, based on the fact that the formation of the Fe xxi forbidden line requires a critical temperature (∼11.5 MK) and density. Moreover, the line shows a non-thermal broadening and a blueshift in the early phase. It suggests that magnetic reconnection at that time has initiated; it not only heats the MFR and, at the same time, produces a non-thermal broadening of the Fe xxi line but also produces the poloidal flux, leading to the ascension of the MFRs.

  5. High flux and high resolution VUV beam line for synchrotron radiation

    Wilcke, H.; Boehmer, W.; Schwentner, N.

    1982-04-01

    A beam line has been optimized for high flux and high resolution in the wavelength range from 30 nm to 300 nm. Sample chambers for luminescence spectroscopy on gaseous, liquid and solid samples and for photoelectron spectroscopy have been integrated. The synchrotron radiation from the storage ring DORIS (at DESY, Hamburg) emitted into 50 mrad in horizontal and into 2.2 mrad in vertical direction is focused by a cylindrical and a plane elliptical mirror into the entrance slit of a 2m normal incidence monochromator. The light flux from the exit slit is focused by a rotational elliptic mirror onto the sample yielding a size of the light spot of 4 x 0.15 mm 2 . The light flux at the sample reaches 7 x 10 12 photons nm -1 s -1 at 8 eV photon energy for a current of 100 mA in DORIS. A resolution of 0.007 nm has been obtained. (orig.)

  6. Upper limits of a cosmic infrared background flux as determined by X- and gamma-ray observations on M87

    Schlickeiser, R.; Cambridge Univ.; Harwit, M.; Cornell Univ., Ithaca, NY

    1982-01-01

    Upper limits on the energy density of infrared photons in the radio lobe regions of M87 are derived using measurements of the X-ray and gamma-ray emission. The calculations are based on an inverse Compton scattering model initiated by radio-flux producing electrons. It is shown that the energy density of infrared photons in the radio lobe regions is similar than 2 eV cm -3 . (orig.)

  7. On-line fast flux measurements in the BR2 reactor

    Vermeeren, L.

    2009-01-01

    Since 2001, CEA-Cadarache and the Belgian Nuclear Research Centre SCK-CEN are collaborating on the development and in-pile qualification of subminiature fission chambers (diameter of 1.5 mm). Initially, efforts concentrated on fission chambers for the in-pile measurement of thermal fluxes (with 235 U as fissile material). Meanwhile successful long-term tests of the prototypes have been performed in various environments: in low temperature (40-100 degress Celsius) BR2 pool water (up to a thermal neutron fluence of 3 1 0 21 n/cm 2 ) and in the CALLISTO PWR loop (300 degrees Celsius, 155 bars). The long-term qualification of derived industrial detectors (Photonis CFUZ53) in CALLISTO is still ongoing. However, for various types of irradiations in research reactors, the knowledge of the evolution of the fast neutron flux is even of more interest than the thermal flux data. Therefore the collaboration program was extended to the development and the in-pile qualification of subminiature or miniature fission chambers (with 3 mm diameter) for fast neutron detection, for which 242 Pu was selected as the optimal fissile material. In order to achieve the on-line in-pile measurement of fast neutron flux, the fission chambers will be operated in the Campbelling mode (based on the mean square fluctuation of the detector current). In this mode the gamma induced contribution to the signal can be efficiently suppressed. Moreover, a data processing software will take into account the evolution of the fissile deposit in order to assess on-line the fast flux sensitivity and to correct for the low energy neutron contributions. The final objective is to qualify a Fast Neutron Detector System (FNDS) able to provide on-line data for local fast neutron fluxes in Material Testing Reactors. The on-line measurement of the fast neutron flux would contribute significantly to the characterization of the irradiation conditions during test experiments with materials and innovative fuel elements

  8. On the theory of critical currents and flux flow in superconductors by the mechanism of plastic deformation of the flux-line lattice

    Welch, D.O.

    1999-01-01

    In this paper the author will discuss how the nature of the stress state in the flux-line lattice (FLL) of superconductors arises from the distribution, density, geometry, and strength of pinning centers. Under certain conditions this stress causes the onset of plastic deformation in the FLL for values of the current density below that required for flux-flow by general depinning. He will describe an analytic framework, based on a theory of plasticity of the FLL, which describes the flux-flow characteristics, including the possibility of thermally-activated flow and flux creep

  9. New upper limit to the coronal line emission from the T Tauri star RU Lupi

    Gahm, G F [Stockholm Observatory (Sweden); Lago, M T.V.T. [Universidade do Porto (Portugal). Grupo de Matematica Aplicada; Penston, M V [ESTEC, European Space Agency, Villafranca Satellite Tracking Station, Madrid, (Spain)

    1981-05-01

    A high dispersion AAT spectrogram sets an upper limit on the (Fe x) emission line lambda 6374.5 A in the T Tauri star RU Lupi. The intensity of any 10/sup 6/ K corona in this star is less than 600 times that of the Sun compared to a chromosphere and transition region of 3 x 10/sup 3/ to 2 x 10/sup 5/ K gas 10/sup 6/ times stronger than the Sun's. The important theoretical implications are noted.

  10. Relativistic electron flux dropout due to field line curvature during the storm on 1 June 2013

    Kang, S. B.; Fok, M. C. H.; Engebretson, M. J.; Li, W.; Glocer, A.

    2017-12-01

    Significant electron flux depletion over a wide range of L-shell and energy, referred as a dropout, was observed by Van Allen Probes during the storm main phase on June 1, 2013. During the same period, MeV electron precipitation with isotropic pitch-angle distribution was also observed in the evening sector from POES but no EMIC waves were detected from either space- or ground-based magnetometers. Based on Tsyganenko empirical magnetic field model, magnetic field lines are highly non-dipolar and stretched at the night side in the inner magnetosphere. This condition can break the first adiabatic invariant (conservation of magnetic moment) and generate pitch-angle scattering of relativistic electron to the loss cone. To understand the relative roles of different physical mechanisms on this dropout event, we simulate flux and phase space density of relativistic electrons with event specific plasma wave intensities using the Comprehensive Inner Magnetosphere and Ionosphere (CIMI) model, as a global 4-D inner magnetosphere model. We also employ pitch-angle scattering due to field line curvature in the CIMI model. We re-configure magnetic field every minute and update electric field every 20 seconds to capture radial transport. CIMI-simulation with pitch-angle scattering due to field line curvature shows more depletion of relativistic electron fluxes and better agreement to observation than CIMI-simulation with radial transport only. We conclude that pitch-angle scattering due to field line curvature is one of the dominant processes for the relativistic electron flux dropout.

  11. Polarisation of auroral emission lines in the Earth's upper atmosphere : first results and perspectives

    Lamy, H.; Barthelemy, M.; Simon Wedlund, C.; Lilensten, J.; Bommier, V.

    2011-12-01

    Polarisation of light is a key observable to provide information about asymmetry or anisotropy within a radiative source. Following the pioneering and controversial work of Duncan in 1959, the polarisation of auroral emission lines in the Earth's upper atmosphere has been overlooked for a long time, even though the red intense auroral line (6300Å) produced by collisional impacts with electrons precipitating along magnetic field lines is a good candidate to search for polarisation. This problem was investigated again by Lilensten et al (2006) and observations were obtained by Lilensten et al (2008) confirming that the red auroral emission line is polarised. More recent measurements obtained by Barthélemy et al (2011) are presented and discussed. The results are compared to predictions of the theoretical work of Bommier et al (2011) and are in good agreement. Following these encouraging results, a new dedicated spectropolarimeter is currently under construction between BIRA-IASB and IPAG to provide simultaneously the polarisation of the red line and of other interesting auroral emission lines such as N2+ 1NG (4278Å), other N2 bands, etc... Perspectives regarding the theoretical polarisation of some of these lines will be presented. The importance of these polarisation measurements in the framework of atmospheric modeling and geomagnetic activity will be discussed.

  12. Adaptive control based on an on-line parameter estimation of an upper limb exoskeleton.

    Riani, Akram; Madani, Tarek; Hadri, Abdelhafid El; Benallegue, Abdelaziz

    2017-07-01

    This paper presents an adaptive control strategy for an upper-limb exoskeleton based on an on-line dynamic parameter estimator. The objective is to improve the control performance of this system that plays a critical role in assisting patients for shoulder, elbow and wrist joint movements. In general, the dynamic parameters of the human limb are unknown and differ from a person to another, which degrade the performances of the exoskeleton-human control system. For this reason, the proposed control scheme contains a supplementary loop based on a new efficient on-line estimator of the dynamic parameters. Indeed, the latter is acting upon the parameter adaptation of the controller to ensure the performances of the system in the presence of parameter uncertainties and perturbations. The exoskeleton used in this work is presented and a physical model of the exoskeleton interacting with a 7 Degree of Freedom (DoF) upper limb model is generated using the SimMechanics library of MatLab/Simulink. To illustrate the effectiveness of the proposed approach, an example of passive rehabilitation movements is performed using multi-body dynamic simulation. The aims is to maneuver the exoskeleton that drive the upper limb to track desired trajectories in the case of the passive arm movements.

  13. Small compression modulus of the flux line lattice and large density fluctuations at high fields may explain peak effect

    Brandt, E.H.

    1976-01-01

    The elastic properties of the flux line lattice in Type II superconductors as calculated from the Ginsburg-Landau theory are discussed. They are non-local on a length scale much larger than the flux line distance and divergent at Hsub(c2). The compression modulus may become much smaller than its long-wavelength limit, B 2 /4π, and if the deformation is not homogeneous, at Hsub(c2) the modulus vanishes as (Hsub(c2) - B) 2 . At arbitrary induction the compression modulus of strain waves with wavelengths of several flux line distances is of the order of the (small) shear modulus. (author)

  14. Thermal depinning and melting of the flux-line lattice in high-Tc superconductors

    Brandt, E.H.

    1991-01-01

    In high-T c superconductors (HTSC) the thermal fluctuation of the vortex lattice (VL) may become large since the vortex lattice is soft due to the strong overlap of the vortex fields and since the temperature T and b high. It was thus argued that the three-dimensional (3D) vortex lattice is thermally entangled and may melt. This type of transition and the consequences of melting are not clear as yet since the always present pinning of the vortex ores by material inhomogeneities may cause similar disorder. In HTSC the pinning energy may become comparable with k B T because the coherence length ξ(vortex radius) is small and t may be high. Therefore, thermally activated depinning competes with possible effects of flux melting, and the irreversibility line in the B-T-plane (B = magnetic field) should better be called depinning line. In this paper it is argued that theories predicting new phases of vortex matter (flux solid, flux liquid, vortex plasma, vortex glass, and hexatic vortex glass) may be improved by replacing the 2D straight-vortex interaction by the correct 3D interaction between all vortex segments

  15. Experimental characterization of the flux-line lattice in superconducting V3Si

    Christen, D.; Chang, Y.; Kerchner, H.; Larson, B.; Narayan, J.; SeKula, S.

    1983-01-01

    Several microscopic properties of the flux-line lattice (FLL) in three separate single crystals of V 3 Si have been investigated by means of small-angle neutron diffraction. These low-field FLL characterizations have been correlated with the following material and superconducting properties: the real crystal symmetry parallel to the applied magnetic field; the micro-structure as determined by TEM; magnetic irreversibilities in the mixed state; reversible flux-line motion in ac response; martensitic structural transformation observed by X-ray diffraction. The three samples, V 3 Si-MP3, -MP4, and -MP5 possessed different defect structures, and this was manifested foremost in the FLL perfection. At low field (B 0-.5 T, but a highly mosaic, nearly polycrystalline FLL at lower fields. Sample MP4 contained large (500-1000 A) incoherent precipitates, and showed only a polycrystalline FLL at low field. In both MP3 and MP5, distinct anisotropic correlations were observed between the FLL morphology and the real-crystal direction along the applied field. The FLL perfection was strongly dependent on the growth history. The peak width history dependence for two different scattering geometries can be qualitatively modeled by proposed flux-pinning mechanisms. Quantitative comparisons with critical current measurements, however, are not totally reconcilable

  16. Biodiversity and climate change: consequences for upper tree line in Slovakia

    Minďaš Jozef

    2016-09-01

    Full Text Available Study of the effects of climate change on upper tree limit has mainly focused on the diversity of tree species as a result of the ability of species to tolerate temperature and moisture changes as well as some effects of disturbance regime changes. The tree species diversity changes due to climate change has been analysed via gap model and biodiversity indices. Gap models are individually based on simulations of establishment, growth, and mortality of each tree on the forest plot. Input ecological data for model calculations have been taken from the permanent research plots located in primeval forests in mountainous regions in Slovakia. The results of regional scenarios of the climatic change for the territory of Slovakia have been used, from which the values according to the CGCM3.1 (global model, KNMI and MPI (regional models. Model results for conditions of the climate change scenarios suggest a shift of the upper forest limit to the region of the present subalpine zone, in supramontane zone. The most significant tree species diversity changes have been identified for the upper tree line and current belt of dwarf pine (Pinus mugo occurrence. Hill’s index of biodiversity in the upper forest line increased by 30 – 35% for horizon of 2050, resp. by 45 – 50% modeled for the horizon of 2075. Calculated values of Shannon’s index show an even higher increase due to climate change. For horizon 2050 is a roughly of three fold increase and horizon for 2075 by almost fivefold increase in the value of the index. Results from the gap model indicate the increase of tree species diversity 2 – 2,5 times.

  17. Balance Mass Flux and Velocity Across the Equilibrium Line in Ice Drainage Systems of Greenland

    Zwally, H. Jay; Giovinetto, Mario B.; Koblinsky, Chester J. (Technical Monitor)

    2001-01-01

    Estimates of balance mass flux and the depth-averaged ice velocity through the cross-section aligned with the equilibrium line are produced for each of six drainage systems in Greenland. (The equilibrium line, which lies at approximately 1200 m elevation on the ice sheet, is the boundary between the area of net snow accumulation at higher elevations and the areas of net melting at lower elevations around the ice sheet.) Ice drainage divides and six major drainage systems are delineated using surface topography from ERS (European Remote Sensing) radar altimeter data. The net accumulation rate in the accumulation zone bounded by the equilibrium line is 399 Gt/yr and net ablation rate in the remaining area is 231 Gt/yr. (1 GigaTon of ice is 1090 kM(exp 3). The mean balance mass flux and depth-averaged ice velocity at the cross-section aligned with the modeled equilibrium line are 0.1011 Gt kM(exp -2)/yr and 0.111 km/yr, respectively, with little variation in these values from system to system. The ratio of the ice mass above the equilibrium line to the rate of mass output implies an effective exchange time of approximately 6000 years for total mass exchange. The range of exchange times, from a low of 3 ka in the SE drainage system to 14 ka in the NE, suggests a rank as to which regions of the ice sheet may respond more rapidly to climate fluctuations.

  18. Spectroscopic Diagnostics of Solar Magnetic Flux Ropes Using Iron Forbidden Line

    Cheng, X.; Ding, M. D.

    2016-01-01

    In this Letter, we present Interface Region Imaging Spectrograph Fe XXI 1354.08 A forbidden line emission of two magnetic flux ropes (MFRs) that caused two fast coronal mass ejections with velocities of $\\ge$1000 km s$^{-1}$ and strong flares (X1.6 and M6.5) on 2014 September 10 and 2015 June 22, respectively. The EUV images at the 131 A and 94 A passbands provided by the Atmospheric Imaging Assembly on board Solar Dynamics Observatory reveal that both MFRs initially appear as suspended hot c...

  19. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Upper Coast of Texas: ESIL (ESI Shoreline Types - Lines)

    National Oceanic and Atmospheric Administration, Department of Commerce — The ESIL data set contains lines representing the shoreline and coastal habitats of the Upper Coast of Texas, classified according to the Environmental Sensitivity...

  20. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Upper Coast of Texas: HYDRO (Hydrography Lines and Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector lines and polygons representing coastal hydrography used in the creation of the Environmental Sensitivity Index (ESI) for the Upper...

  1. NEW UPPER AND LOWER BOUNDS LINE OF SIGHT PATH LOSS MODELS FOR MOBILE PROPAGATION IN BUILDINGS

    Supachai Phaiboon

    2017-11-01

    Full Text Available This paper proposes a method to predict line-of-sight (LOS path loss in buildings. We performed measurements in two different type of buildings at a frequency of 1.8 GHz and propose new upper and lower bounds path loss models which depend on max and min values of sample path loss data. This makes our models limit path loss within the boundary lines. The models include time-variant effects such as people moving and cars in parking areas with their influence on wave propagation that is very high.  The results have shown that the proposed models will be useful for the system and cell design of indoor wireless communication systems.

  2. Elastic energy of the flux lines in the matter. The interaction energy

    Dolocan, Voicu

    1999-01-01

    A theoretical treatment of the interaction between the bodies, by using the elastic coupling through the flux lines, is presented. We show that the elastic coupling through the flux lines gives an interaction energy between two superconductor or magnetic pieces, which is inversely proportional to the distance between the two bodies. We extend this concept to the gravitational and electrical interaction. For the electrical interaction one obtains that the statics interaction energy is inversely proportional to the distance between the charges, as in the Coulomb's law, while the oscillatory interaction is inversely proportional to the third power of the distance between the charged particles. This means that at shorter distance an attraction between the two charged particles of the same sign, may appear if the oscillatory energy of interaction is larger than the statics energy of interaction. In addition, the oscillatory interaction appears only as a virtual process. We apply these results to the deuteron and to the electron pairs in superconductors. Also, for the gravitation one obtains that the interaction energy is inversely proportional to the distance between the centers of the two bodies as in Newton's law. (author)

  3. Experimental characterization of the flux-line lattice in superconducting V3Si

    Christen, D.K.; Kerchner, H.R.; Narayan, J.; Chang, Y.K.; Larson, B.C.; Sekula, S.T.

    1982-01-01

    Several microscopic properties of the flux-line lattice (FLL) in three separate single crystals of V 3 Si have been investigated by means of small-angle neutron diffraction. These low-field FLL characterizations have been correlated with the following material and superconducting properties: (1) the real crystal symmetry parallel to the applied magnetic field; (2) the micro-structure as determined by TEM; (3) magnetic irreversibilities in the mixed state; (4) reversible flux-line motion in ac response; and (5) martensitic structural transformation observed by x-ray diffraction. The three samples, V 3 Si-MP3, -MP4, and -MP5 possessed different defect structures, and this was manifested foremost in the FLL perfection. At low field (B 0 K, only MP3, which is free of second-phase precipitates, showed a highly resolved FLL. Sample MP5 contains a low density of small (200 A) coherent precipitates, and revealed well-defined FLL Bragg peaks for B greater than or equal to 0.5 T, but a highly mosaic, nearly polycrystalline FLL at lower fields. Sample MP4 contained large (500 to 1000 A) incoherent precipitates, and showed only a polycrystalline FLL at low field. In both MP3 and MP5, distinct anisotropic correlations were observed between the FLL morphology and the real-crystal direction along the applied field. The FLL perfection was strongly dependent on the growth history. The peak width history dependence for two different scattering geometries can be qualitatively modeled by proposed flux-pinning mechanisms. Quantitative comparisons with critical current measurements, however, are not totally reconcilable

  4. Geothermal Heat Flux and Upper Mantle Viscosity across West Antarctica: Insights from the UKANET and POLENET Seismic Networks

    O'Donnell, J. P.; Dunham, C.; Stuart, G. W.; Brisbourne, A.; Nield, G. A.; Whitehouse, P. L.; Hooper, A. J.; Nyblade, A.; Wiens, D.; Aster, R. C.; Anandakrishnan, S.; Huerta, A. D.; Wilson, T. J.; Winberry, J. P.

    2017-12-01

    Quantifying the geothermal heat flux at the base of ice sheets is necessary to understand their dynamics and evolution. The heat flux is a composite function of concentration of upper crustal radiogenic elements and flow of heat from the mantle into the crust. Radiogenic element concentration varies with tectonothermal age, while heat flow across the crust-mantle boundary depends on crustal and lithospheric thicknesses. Meanwhile, accurately monitoring current ice mass loss via satellite gravimetry or altimetry hinges on knowing the upper mantle viscosity structure needed to account for the superimposed glacial isostatic adjustment (GIA) signal in the satellite data. In early 2016 the UK Antarctic Network (UKANET) of 10 broadband seismometers was deployed for two years across the southern Antarctic Peninsula and Ellsworth Land. Using UKANET data in conjunction with seismic records from our partner US Polar Earth Observing Network (POLENET) and the Antarctic Seismographic Argentinian Italian Network (ASAIN), we have developed a 3D shear wave velocity model of the West Antarctic crust and uppermost mantle based on Rayleigh and Love wave phase velocity dispersion curves extracted from ambient noise cross-correlograms. We combine seismic receiver functions with the shear wave model to help constrain the depth to the crust-mantle boundary across West Antarctica and delineate tectonic domains. The shear wave model is subsequently converted to temperature using a database of densities and elastic properties of minerals common in crustal and mantle rocks, while the various tectonic domains are assigned upper crustal radiogenic element concentrations based on their inferred tectonothermal ages. We combine this information to map the basal geothermal heat flux variation across West Antarctica. Mantle viscosity depends on factors including temperature, grain size, the hydrogen content of olivine and the presence of melt. Using published mantle xenolith and magnetotelluric

  5. Flux

    Ravn, Ib

    . FLUX betegner en flyden eller strømmen, dvs. dynamik. Forstår man livet som proces og udvikling i stedet for som ting og mekanik, får man et andet billede af det gode liv end det, som den velkendte vestlige mekanicisme lægger op til. Dynamisk forstået indebærer det gode liv den bedst mulige...... kanalisering af den flux eller energi, der strømmer igennem os og giver sig til kende i vore daglige aktiviteter. Skal vores tanker, handlinger, arbejde, samvær og politiske liv organiseres efter stramme og faste regelsæt, uden slinger i valsen? Eller skal de tværtimod forløbe ganske uhindret af regler og bånd...

  6. Comparison of real-time BTEX flux measurements to reported emission inventories in the Upper Green River Basin, Wyoming.

    Edie, R.; Robertson, A.; Murphy, S. M.; Soltis, J.; Field, R. A.; Zimmerle, D.; Bell, C.

    2017-12-01

    Other Test Method 33a (OTM-33a) is an EPA-developed near-source measurement technique that utilizes a Gaussian plume inversion to calculate the flux of a point source 20 to 200 meters away. In 2014, the University of Wyoming mobile laboratory—equipped with a Picarro methane analyzer and an Ionicon Proton Transfer Reaction Time of Flight Mass Spectrometer—measured methane and BTEX fluxes from oil and gas operations in the Upper Green River Basin (UGRB), Wyoming. In this study, OTM-33a BTEX flux measurements are compared to BTEX emissions reported by operators in the Wyoming Department of Environmental Quality (WY-DEQ) emission inventory. On average, OTM-33a measured BTEX fluxes are almost twice as high as those reported in the emission inventory. To further constrain errors in the OTM-33a method, methane test releases were performed at the Colorado State University Methane Emissions Test and Evaluation Center (METEC) in June of 2017. The METEC facility contains decommissioned oil and gas equipment arranged in realistic well pad layouts. Each piece of equipment has a multitude of possible emission points. A Gaussian fit of measurement error from these 29 test releases indicate the median OTM-33a measurement quantified 55% of the metered flowrate. BTEX results from the UGRB campaign and inventory analysis will be presented, along with a discussion of errors associated with the OTM-33a measurement technique. Real-time BTEX and methane mixing ratios at the measurement locations (which show a lack of correlation between VOC and methane sources in 20% of sites sampled) will also be discussed.

  7. Critical heat flux of water in vertical tubes with an upper plenum and a closed bottom

    Kim, Hong Chae; Baek, Won Pil; Chang, Soon Heung

    2000-01-01

    An experimental study is conducted for vertical round tubes with an upper plenum and a closed bottom to investigate CHF behavior and CHF onset location under the counter-current condition. The measured CHF values are well predicted by general Wallis type flooding correlations. A 1-D steady state analytical flooding model for thermosyphon by El-Genk and Saber was assessed with the data and the liquid film thickness at the liquid entrance was calculated. The CHF onset position becomes different with L/D and D, and liquid entrance geometry affects only CHF values not CHF onset positions

  8. Can anterior junction line be used to distinguish right middle from right upper lobe on CT scan?

    Cha, Jae Heon; Suh, Ja Young; Jo, Jin Man; Jeong, Hyeon Jo; Cheon, Mal Soon; Lee, Chul Woo; Yoon, Soon Min

    1997-01-01

    To evalvate the usefulness on a CT chest scan, of the anterior junction line as an anatomical landmark to distinguish the right middle and the right upper lobe We found that the anterior junction line has a constant anatomical relationship with the right upper and middle lobe, and with this in mind, analysed connvcntional CT films of 86 patients with normal lung(group A) and 30 with architectural distortion(group B). On a series of slices, we compared the location of slice 1 with that of slice 2(slice 1:the slice which includes the lowest portion of the anterior junction line, slice 2:the initial slice, in which the right middle lobe occupies the whole of the lung anterior to the right major fissure). In group A(n=86), the right upper lobe, as seen in the anteromedial zone of slice 1, was present in 83 cases(96.5%). The right upper lobe on slice 1 was absent in two cases(2.3%) in which a minor fissure was almost completely abent. In group B(n=30), the right upper lobe on slice 1 was absent in 19 cases(63.3%). We suggest that on a CT chest scan, the anterior junction line can be used as an anatomical landmark in the differentiation of the right middle from the right upper lobe, and as an indicator of the presence of architectural distortion

  9. Mechanical response of the flux lines in ceramic YBa2Cu3O7-δ

    Luzuriaga, J.; André, M.-O.; Benoit, W.

    1992-06-01

    We have studied the mechanical response of the flux-line lattice (FLL) in ceramic samples of YBa2Cu3O7 by means of a low-frequency forced pendulum. The internal friction and elastic modulus variation of the FLL have been measured as a function of temperature for different values of the applied stress. A somewhat different behavior was observed whether a zero-field-cooling or field-cooling procedure was followed. Measurements of the internal friction and elastic modulus as a function of the applied stress at constant temperature show amplitude-dependent dissipation, with a maximum dissipation at intermediate values of the stress. This dependence is well fitted by a rheological model of extended dry friction, if we restrict ourselves to the dissipation and modulus at fixed temperature. The agreement is not so good when attempting to extend the model to fit the temperature dependence.

  10. Heat flux estimation for neutral beam line components using inverse heat conduction procedures

    Bharathi, P.; Prahlad, V.; Quereshi, K.; Bansal, L.K.; Rambabu, S.; Sharma, S.K.; Parmar, S.; Patel, P.J.; Baruah, U.K.; Patel, Ravi

    2015-01-01

    In this work, we describe and compare the analytical IHCP methods such-as semi-infinite method, finite slab method and a numerical method called Stolz method for estimating the incident heat flux from the experimentally measured temperature data. In case of analytical methods, the finite time response of the sensor is needed to be accounted for an accurate power density estimations. The modified models corrected for the response time of the sensors are also discussed in this paper. Application of these methods using example temperature waveforms obtained on the SST1-NBI test stand is presented and discussed. For choosing the suitable method for the calorimetry on beam line components, the estimated results are also validated using the ANSYS analysis done on these beam Iine components. As a conclusion, the finite slab method corrected for the influence of the sensor response time found out to be the most suitable method for the inversion of temperature data in case of neutral beam line components

  11. Prevalence and predictors of columnar lined esophagus in gastroesophageal reflux disease (GERD) patients undergoing upper endoscopy.

    Balasubramanian, Gokulakrishnan; Singh, Mandeep; Gupta, Neil; Gaddam, Srinivas; Giacchino, Maria; Wani, Sachin B; Moloney, Brian; Higbee, April D; Rastogi, Amit; Bansal, Ajay; Sharma, Prateek

    2012-11-01

    Chronic gastroesophageal reflux disease (GERD) is a risk factor for Barrett's esophagus (BE), the most important surrogate marker for the development of esophageal adenocarcinoma (EAC). The need to document the presence of intestinal metaplasia in esophageal biopsies from a columnar lined esophagus (CLE) to diagnose BE is debated. The objective of this study was to prospectively evaluate the prevalence and risk factors of CLE in a large cohort of GERD patients undergoing upper endoscopy. Consecutive patients presenting to the endoscopy unit at a tertiary referral center for their index upper endoscopy for evaluation of GERD symptoms were enrolled in this prospective cohort study. Patients were asked to complete a validated GERD questionnaire that documents the onset of GERD symptoms (heartburn and acid regurgitation) and grades the frequency and severity of symptoms experienced over the past year. Demographic information, body mass index, and use of aspirin/nonsteroidal antiinflammatory drugs were recorded. Endoscopic details including length of CLE, presence and size of hiatal hernia were noted. Patients with CLE (cases) were compared with those without CLE (controls) using Fischer's exact test and t-test. All factors that were statistically significant (PGERD symptoms were prospectively enrolled. On index endoscopy, the prevalence of CLE was 23.3%, whereas of CLE with documented intestinal metaplasia was 14.1%. On univariate analysis, male gender, Caucasian race, heartburn duration of >5 years, presence and size of hiatal hernia were significantly associated with the presence of CLE compared with controls (P5 years (odds ratio (OR): 1.50, 95% confidence interval (CI): 1.07-2.09, P=0.01), Caucasian race (OR: 2.40, 95% CI: 1.42-4.03, P=0.001), and hiatal hernia (OR: 2.07, 95% CI: 1.50-2.87, PGERD patients are diagnosed with this lesion. Enrolling all these patients in surveillance programs would have significant ramifications on health-care resources.

  12. The role of the upper tidal estuary in wetland blue carbon storage and flux

    Krauss, Ken W.; Noe, Gregory B.; Duberstein, Jamie A.; Conner, William H.; Stagg, Camille L.; Cormier, Nicole; Jones, Miriam C.; Bernhardt, Christopher E.; Lockaby, B. Graeme; From, Andrew S.; Doyle, Thomas W.; Day, Richard H.; Ensign, Scott H.; Pierfelice, Katherine N.; Hupp, Cliff R.; Chow, Alex T.; Whitbeck, Julie L.

    2018-01-01

    Carbon (C) standing stocks, C mass balance, and soil C burial in tidal freshwater forested wetlands (TFFW) and TFFW transitioning to low‐salinity marshes along the upper estuary are not typically included in “blue carbon” accounting, but may represent a significant C sink. Results from two salinity transects along the tidal Waccamaw and Savannah rivers of the US Atlantic Coast show total C standing stocks were 321‐1264 Mg C ha‐1 among all sites, generally shifting to greater soil storage as salinity increased. Carbon mass balance inputs (litterfall, woody growth, herbaceous growth, root growth, surface accumulation) minus C outputs (surface litter and root decomposition, gaseous C) over a period of up to 11 years were 340‐900 g C m‐2 yr‐1. Soil C burial was variable (7‐337 g C m‐2 yr‐1), and lateral C export was estimated as C mass balance minus soil C burial as 267‐849 g C m‐2yr‐1. This represents a large amount of C export to support aquatic biogeochemical transformations. Despite reduced C persistence within emergent vegetation, decomposition of organic matter, and higher lateral C export, total C storage increased as forests converted to marsh with salinization. These tidal river wetlands exhibited high N mineralization in salinity‐stressed forested sites and considerable P mineralization in low salinity marshes. Large C standing stocks and rates of C sequestration suggest that TFFW and oligohaline marshes are considerably important globally to coastal C dynamics and in facilitating energy transformations in areas of the world in which they occur.

  13. Small angle neutron scattering studies of the flux line lattices in the borocarbide superconductors

    Eskildsen, Morten Ring

    1998-12-01

    This thesis describes small angle neutron scattering studies of the flux line lattice (FLL) in the following members of the borocarbide superconductors: YNi{sub 2}B{sub 2}C, ErNi{sub 2}B{sub 2}C, TmNi{sub 2}B{sub 2}C, LuNi{sub 2}B{sub 2}C, Y{sub 0.75}Lu{sub 0.25}Ni{sub 2}B{sub 2}C and Lu(Ni{sub 1-x}CO{sub x}){sub 2}B{sub 2}C with x = 1.5 - 9%. Of the materials ErN{sub 2}B{sub 2}C and TmNi{sub 2}B{sub 2}C exhibits coexisting superconductivity and magnetic ordering. Three main conclusions can be derived from the results in this thesis. Existence of a low field hexagonal to square symmetry transition of the FLL, ubiquitous to the superconducting borocarbides, magnetic and non-magnetic alike. This symmetry transition is due to the four-fold anisotropy of the Fermi surface, distorting the screening currents towards a square flow pattern. This four-fold anisotropy together with non-local electrodynamics induces a transition to a square FLL, as the field is increased. Changing the non-locality range shifts the square to hexagonal transition onset field. A static disordering of the FLL in YNi{sub 2}B{sub 2}C and LuNi{sub 2}B{sub 2}C. In these materials one observes a well ordered FLL, with a longitudinal correlation length exceeding 100 flux line spacings. As the applied field is increased the longitudinal correlation length, increases with field up to H/H{sub c2} {approx} 0.2. Above this field the FLL correlation length slowly starts to fall off, in contradiction to theoretical models. The existence of complex interactions between the magnetic state and the FLL in TmNi{sub 2}B{sub 2}C. This is signalled by coinciding changes in the FLL symmetry and in the magnetic structure. The FLL show a two-step symmetry transition from square to rhombic and then hexagonal with increased field. In addition, the FLL reflectivity shows distinct peaks as the thulium ions orders magnetically at T{sub N} and across the field driven magnetic transition. No explanation for this behaviour

  14. Small angle neutron scattering studies of the flux line lattices in the borocarbide superconductors

    Eskildsen, Morten Ring

    1998-12-01

    This thesis describes small angle neutron scattering studies of the flux line lattice (FLL) in the following members of the borocarbide superconductors: YNi 2 B 2 C, ErNi 2 B 2 C, TmNi 2 B 2 C, LuNi 2 B 2 C, Y 0.75 Lu 0.25 Ni 2 B 2 C and Lu(Ni 1-x CO x ) 2 B 2 C with x = 1.5 - 9%. Of the materials ErN 2 B 2 C and TmNi 2 B 2 C exhibits coexisting superconductivity and magnetic ordering. Three main conclusions can be derived from the results in this thesis. Existence of a low field hexagonal to square symmetry transition of the FLL, ubiquitous to the superconducting borocarbides, magnetic and non-magnetic alike. This symmetry transition is due to the four-fold anisotropy of the Fermi surface, distorting the screening currents towards a square flow pattern. This four-fold anisotropy together with non-local electrodynamics induces a transition to a square FLL, as the field is increased. Changing the non-locality range shifts the square to hexagonal transition onset field. A static disordering of the FLL in YNi 2 B 2 C and LuNi 2 B 2 C. In these materials one observes a well ordered FLL, with a longitudinal correlation length exceeding 100 flux line spacings. As the applied field is increased the longitudinal correlation length, increases with field up to H/H c2 ∼ 0.2. Above this field the FLL correlation length slowly starts to fall off, in contradiction to theoretical models. The existence of complex interactions between the magnetic state and the FLL in TmNi 2 B 2 C. This is signalled by coinciding changes in the FLL symmetry and in the magnetic structure. The FLL show a two-step symmetry transition from square to rhombic and then hexagonal with increased field. In addition, the FLL reflectivity shows distinct peaks as the thulium ions orders magnetically at T N and across the field driven magnetic transition. No explanation for this behaviour exists at the present. (au)

  15. New measurement system for on line in core high-energy neutron flux monitoring in materials testing reactor conditions

    Geslot, B.; Vermeeren, L.; Filliatre, P.; Lopez, A. Legrand; Barbot, L.; Jammes, C.; Bréaud, S.; Oriol, L.; Villard, J.-F.

    2011-03-01

    Flux monitoring is of great interest for experimental studies in material testing reactors. Nowadays, only the thermal neutron flux can be monitored on line, e.g., using fission chambers or self-powered neutron detectors. In the framework of the Joint Instrumentation Laboratory between SCK-CEN and CEA, we have developed a fast neutron detector system (FNDS) capable of measuring on line the local high-energy neutron flux in fission reactor core and reflector locations. FNDS is based on fission chambers measurements in Campbelling mode. The system consists of two detectors, one detector being mainly sensitive to fast neutrons and the other one to thermal neutrons. On line data processing uses the CEA depletion code DARWIN in order to disentangle fast and thermal neutrons components, taking into account the isotopic evolution of the fissile deposit. The first results of FNDS experimental test in the BR2 reactor are presented in this paper. Several fission chambers have been irradiated up to a fluence of about 7 × 1020 n/cm2. A good agreement (less than 10% discrepancy) was observed between FNDS fast flux estimation and reference flux measurement.

  16. New measurement system for on line in core high-energy neutron flux monitoring in materials testing reactor conditions

    Geslot, B.; Filliatre, P.; Barbot, L.; Jammes, C.; Breaud, S.; Oriol, L.; Villard, J.-F. [CEA, DEN, Cadarache, SPEx/LDCI, F-13108 Saint-Paul-lez-Durance (France); Vermeeren, L. [SCK-CEN, Boeretang 200, B-2400 Mol (Belgium); Lopez, A. Legrand [CEA, DEN, Saclay, SIREN/LECSI, F-91400 Saclay (France)

    2011-03-15

    Flux monitoring is of great interest for experimental studies in material testing reactors. Nowadays, only the thermal neutron flux can be monitored on line, e.g., using fission chambers or self-powered neutron detectors. In the framework of the Joint Instrumentation Laboratory between SCK-CEN and CEA, we have developed a fast neutron detector system (FNDS) capable of measuring on line the local high-energy neutron flux in fission reactor core and reflector locations. FNDS is based on fission chambers measurements in Campbelling mode. The system consists of two detectors, one detector being mainly sensitive to fast neutrons and the other one to thermal neutrons. On line data processing uses the CEA depletion code DARWIN in order to disentangle fast and thermal neutrons components, taking into account the isotopic evolution of the fissile deposit. The first results of FNDS experimental test in the BR2 reactor are presented in this paper. Several fission chambers have been irradiated up to a fluence of about 7 x 10{sup 20} n/cm{sup 2}. A good agreement (less than 10% discrepancy) was observed between FNDS fast flux estimation and reference flux measurement.

  17. New measurement system for on line in core high-energy neutron flux monitoring in materials testing reactor conditions

    Geslot, B.; Filliatre, P.; Barbot, L.; Jammes, C.; Breaud, S.; Oriol, L.; Villard, J.-F.; Vermeeren, L.; Lopez, A. Legrand

    2011-01-01

    Flux monitoring is of great interest for experimental studies in material testing reactors. Nowadays, only the thermal neutron flux can be monitored on line, e.g., using fission chambers or self-powered neutron detectors. In the framework of the Joint Instrumentation Laboratory between SCK-CEN and CEA, we have developed a fast neutron detector system (FNDS) capable of measuring on line the local high-energy neutron flux in fission reactor core and reflector locations. FNDS is based on fission chambers measurements in Campbelling mode. The system consists of two detectors, one detector being mainly sensitive to fast neutrons and the other one to thermal neutrons. On line data processing uses the CEA depletion code DARWIN in order to disentangle fast and thermal neutrons components, taking into account the isotopic evolution of the fissile deposit. The first results of FNDS experimental test in the BR2 reactor are presented in this paper. Several fission chambers have been irradiated up to a fluence of about 7 x 10 20 n/cm 2 . A good agreement (less than 10% discrepancy) was observed between FNDS fast flux estimation and reference flux measurement.

  18. Contraction and Expansion of the Upper Zambezi Wetlands in Response to Precipitation Regime Changes and Impacts on Carbon, Energy and Water Fluxes

    Lowman, L.; Barros, A. P.

    2017-12-01

    The Upper Zambezi River Basin (UZRB) serves as the headwater catchment of the fourth-largest river in Africa, provides essential freshwater resources to arid and semi-arid regions within its boundaries, and recharges the Northern Kalahari Aquifer. Shallow and clayey soils give way to seasonal waterlogging, especially along drainage lines, favoring the establishment of wetlands. Woodland savanna, grasslands and miombo dominate the UZRB's diverse ecosystem, marking a complex transition zone between the Congo tropical rainforest and the Kalahari Desert that reflects spatial rainfall gradients. Satellite imagery shows that permanent wetlands are located in low-lying convergence zones in the northeast and northwest corners of UZRB where surface-groundwater interactions are most vigorous. However, orographic precipitation gradients cannot fully explain interannual changes in wetland area and vegetation density. We hypothesize that changes in vegetation density result from nonlinear interactions and feedbacks among precipitation, canopy biophysical properties, soil moisture and groundwater processes modulated by topography and regional hydrogeology. This work aims to understand how changes in vegetation density, particularly in and around permanent and intermittent wetlands, impact carbon, energy and water fluxes. Using the MODIS Nadir BRDF-Adjusted Reflectance product, a seasonally-varying wetland class is derived that reflects inter-annual precipitation and groundwater variability. The Duke Coupled Hydrology Model with Prognostic Vegetation is adapted to include C4 photosynthesis for the UZRB grasslands and used to simulate changes in canopy density and impacts on gross primary productivity, evapotranspiration, and soil moisture at high spatial and temporal resolution. Initial results using the column-wise model provide a baseline for understanding surface fluxes before incorporating groundwater and subsurface flows crucial to investigating the implicit nonlinearities

  19. Correlation between the line width and the line flux of the double-peaked broad Hα of 3C390.3

    Zhang, Xue-Guang

    2013-03-01

    In this paper, we carefully check the correlation between the line width (second moment) and the line flux of the double-peaked broad Hα of the well-known mapped active galactic nucleus (AGN) 3C390.3 in order to show some further distinctions between double-peaked emitters and normal broad-line AGN. Based on the virialization assumption MBH ∝ RBLR × V2(BLR) and the empirical relation RBLR ∝ L˜0.5, one strong negative correlation between the line width and the line flux of the double-peaked broad lines should be expected for 3C390.3, such as the negative correlation confirmed for the mapped broad-line object NGC 5548, RBLR × V2(BLR) ∝ L˜0.5 × σ2 = constant. Moreover, based on the public spectra around 1995 from the AGN WATCH project for 3C390.3, one reliable positive correlation is found between the line width and the line flux of the double-peaked broad Hα. In the context of the proposed theoretical accretion disc model for double-peaked emitters, the unexpected positive correlation can be naturally explained, due to different time delays for the inner and outer parts of the disc-like broad-line region (BLR) of 3C390.3. Moreover, the virialization assumption is checked and found to be still available for 3C390.3. However, the time-varying size of the BLR of 3C390.3 cannot be expected by the empirical relation RBLR ∝ L˜0.5. In other words, the mean size of the BLR of 3C390.3 can be estimated by the continuum luminosity (line luminosity), while the continuum emission strengthening leads to the size of BLR decreasing (not increasing) in different moments for 3C390.3. Then, we compared our results of 3C390.3 with the previous results reported in the literature for the other double-peaked emitters, and found that before to clearly correct the effects from disc physical parameters varying (such as the effects of disc precession) for long-term observed line spectra, it is not so meaningful to discuss the correlation of the line parameters of double

  20. Upper ocean carbon flux determined by the 234Th approach and sediment traps using size-fractionated POC and 234Th data from the Golf of Mexico

    Hung, Chin-Chang; Roberts, Kimberly A.; Santschi, Peter H.; Guo, Laodong

    2004-01-01

    Size-fractionated particulate 234 Th and particulate organic carbon (POC) fluxes were measured in the Gulf of Mexico during 2000 and 2001 in order to obtain a better estimation of upper ocean organic carbon export out of the euphotic zone within cold core and warm core rings, and to assess the relative merit of sediment trap and POC/ 234 Th methods. In 2000, the flux of POC measured by sediment traps at 120 m ranged from 60 to 148 mg C m -2 d -1 , while 234 Th-derived POC fluxes in large particles (>53 μm) varied from 18 to 61 mg C m -2 d -1 using the ratio of POC/ 234 Th at 120 m, and from 51 to 163 mg C m -2 d -1 using an average ratio of POC/ 234 Th for the upper 120 m water column. In 2001, the fluxes of POC measured by traps deployed at 120 m water depth ranged from 39 to 48 mg C m -2 d -1 , while the 234 Th-derived POC fluxes in large particles (>53 μm) varied from 7 to 37 mg C m -2 d -1 using a ratio of POC/ 234 Th at 120 m, and from 37 to 45 mg C m -2 d -1 using an average ratio of POC/ 234 Th within the 0-120 m interval. The results show that POC fluxes estimated by the 234 Th method using the average ratio of POC/ 234 Th within the euphotic zone are similar to those measured by sediment traps. Furthermore, the results demonstrate that the variability in POC export fluxes estimated by the 234 Th/ 238 U disequilibrium approach is strongly related to the ratio of POC/ 234 Th that is taken, and for which we have independent evidence that it may be controlled by the chemical composition of the suspended particles. The results also reveal that using POC/ 234 Th ratios in small particles may result in an estimate of the POC export flux that is considerably higher than when using POC/ 234 Th ratios in large particles (>53 μm). The POC flux calculated from ratios in large particles is, however, more comparable to the POC flux determined directly by sediment traps, but both of these estimates are much lower than that determined by using the POC/ 234 Th ratios in

  1. A study of the movement of the flux lines in YBa2Cu3O7-δ epitaxial film

    Sha Jian; He Zhenghui; Su Zhengpeng; Zhao Zhanchun; Wang Nanlin

    1991-01-01

    The movements of the flux lines in the YBa 2 Cu 3 O 7-δ epitaxial film have been studied by Hall effect and the broadening of the resistance-temperature curves(R-T curves) in the magnetic field. From the broadened R T curves the exponent relation is obtained between the value of the activation energy of the flux creep and the value of the field. From the measurements of the Hall coefficient R H the unusual variation of the Hall coefficient corresponding to the broadening of the R-T curves is found. All of the variations in the R-T curves as well as the R H -H curves have been also discussed by the vortex glass model, exploring the laws of the flux creep in different ways

  2. sup(234) Th scavenging and particle export fluxes from the upper 100 m of the Arabian Sea

    Sarin, M.M.; Rengarajan, R.; Ramaswamy, V.

    of column primary productivity. Using the sup(234) Th export fluxes and the measured specific activity of sup(234) Th in the sediment traps, we have computed th eparticle and carbon fluxes at 100 m. These results reveal that the particle fluxes determined...

  3. Physical properties in flux line lattice state in MgB2 probed by μSR

    Ohishi, Kazuki; Muranaka, Takahiro; Akimitsu, Jun; Koda, Akihiro; Higemoto, Wataru; Kadono, Ryosuke

    2002-01-01

    We have performed muon spin rotation (μSR) measurements to deduce the magnetic penetration depth λ in the flux line lattice state of MgB 2 microscopically. It is observed that λ shows a quadratic temperature dependence which is predicted for the case of superconducting gap with line nodes. Furthermore, it clearly exhibits a strong field dependence, where λ increases almost linearly with H. These results strongly suggest that the superconducting order parameter in MgB 2 is highly anisotropic. (author)

  4. Non-locality and the flux line lattice square to hexagonal symmetry transition in the borocarbide superconductors

    Eskildsen, M.R.; Fisher, I.R.; Gammel, P.L.

    2000-01-01

    Using small angle neutron scattering we have studied the square to hexagonal flux line lattice symmetry transition in different members of the borocarbide superconductors. The studies were performed using samples of ErNi2B2C, Lu(Ni1-xCox)(2)B2C with cobalt doping levels x = 1.5-9% and Y0.64Lu0.36Ni...

  5. Flux quanta, magnetic field lines, merging – some sub-microscale relations of interest in space plasma physics

    R. A. Treumann

    2011-06-01

    Full Text Available We clarify the notion of magnetic field lines in plasma by referring to sub-microscale (quantum mechanical particle dynamics. It is demonstrated that magnetic field lines in a field of strength B carry single magnetic flux quanta Φ0=h/e. The radius of a field line in the given magnetic field B is calculated. It is shown that such field lines can merge and annihilate only over the length ℓ∥ of their strictly anti-parallel sections, for which case we estimate the power generated. The length ℓ∥ becomes a function of the inclination angle θ of the two merging magnetic flux tubes (field lines. Merging is possible only in the interval 12πθ≤π. This provides a sub-microscopic basis for "component reconnection" in classical macro-scale reconnection. We also find that the magnetic diffusion coefficient in plasma appears in quanta D0m=eΦ0/me=h/me. This lets us conclude that the bulk perpendicular plasma resistivity is limited and cannot be less than η0⊥=μ0eΦ0/me=μ0h/me~10−9 Ohm m. This resistance is an invariant.

  6. Extracellular ATP4- promotes cation fluxes in the J774 mouse macrophage cell line

    Steinberg, T.H.; Silverstein, S.C.

    1987-01-01

    Extracellular ATP stimulates transmembrane ion fluxes in the mouse macrophage cell line J774. In the presence of Mg2+, nonhydrolyzable ATP analogs and other purine and pyrimidine nucleotides do not elicit this response, suggesting the presence of a specific receptor for ATP on the macrophage plasma membrane. One candidate for such a receptor is the ecto-ATPase expressed on these cells. We, therefore, investigated the role of this enzyme in ATP-induced 86 Rb+ efflux in J774 cells. The ecto-ATPase had a broad nucleotide specificity and did not hydrolyze extracellular ATP in the absence of divalent cations. 86 Rb+ efflux was not blocked by inhibition of the ecto-ATPase and did not require Ca2+ or Mg2+. In fact, ATP-stimulated 86 Rb+ efflux was inhibited by Mg2+ and correlated with the availability of ATP4- in the medium. In the absence of divalent cations, the slowly hydrolyzable ATP analogs adenosine 5'-(beta, gamma-imido)triphosphate (AMP-PNP) and adenosine 5'-O-(3-thio)triphosphate (ATP-gamma-S) also stimulated 86 Rb+ efflux, albeit at higher concentrations than that required for ATP4-. Exposure of J774 cells to 10 mM ATP for 45 min caused death of 95% of cells. By this means we selected variant J774 cells that did not exhibit 86 Rb+ efflux in the presence of extracellular ATP but retained ecto-ATPase activity. These results show that the ecto-ATPase of J774 cells does not mediate the effects of ATP on these cells; that ATP4- and not MgATP2- promotes 86 Rb+ efflux from these cells; and that hydrolysis of ATP is not required to effect this change in membrane permeability. These findings suggest that J774 cells possess a plasma membrane receptor which binds ATP4-, AMP-PNP, and ATP-gamma-S, and that the ecto-ATPase limits the effects of ATP on these cells by hydrolyzing Mg-ATP2-

  7. Parallel transport of long mean-free-path plasma along open magnetic field lines: Parallel heat flux

    Guo Zehua; Tang Xianzhu

    2012-01-01

    In a long mean-free-path plasma where temperature anisotropy can be sustained, the parallel heat flux has two components with one associated with the parallel thermal energy and the other the perpendicular thermal energy. Due to the large deviation of the distribution function from local Maxwellian in an open field line plasma with low collisionality, the conventional perturbative calculation of the parallel heat flux closure in its local or non-local form is no longer applicable. Here, a non-perturbative calculation is presented for a collisionless plasma in a two-dimensional flux expander bounded by absorbing walls. Specifically, closures of previously unfamiliar form are obtained for ions and electrons, which relate two distinct components of the species parallel heat flux to the lower order fluid moments such as density, parallel flow, parallel and perpendicular temperatures, and the field quantities such as the magnetic field strength and the electrostatic potential. The plasma source and boundary condition at the absorbing wall enter explicitly in the closure calculation. Although the closure calculation does not take into account wave-particle interactions, the results based on passing orbits from steady-state collisionless drift-kinetic equation show remarkable agreement with fully kinetic-Maxwell simulations. As an example of the physical implications of the theory, the parallel heat flux closures are found to predict a surprising observation in the kinetic-Maxwell simulation of the 2D magnetic flux expander problem, where the parallel heat flux of the parallel thermal energy flows from low to high parallel temperature region.

  8. Relative humidity effects on water vapour fluxes measured with closed-path eddy-covariance systems with short sampling lines

    Fratini, Gerardo; Ibrom, Andreas; Arriga, Nicola

    2012-01-01

    It has been formerly recognised that increasing relative humidity in the sampling line of closed-path eddy-covariance systems leads to increasing attenuation of water vapour turbulent fluctuations, resulting in strong latent heat flux losses. This occurrence has been analyzed for very long (50 m...... from eddy-covariance systems featuring short (4 m) and very short (1 m) sampling lines running at the same clover field and show that relative humidity effects persist also for these setups, and should not be neglected. Starting from the work of Ibrom and co-workers, we propose a mixed method...... and correction method proposed here is deemed applicable to closed-path systems featuring a broad range of sampling lines, and indeed applicable also to passive gases as a special case. The methods described in this paper are incorporated, as processing options, in the free and open-source eddy...

  9. U-Pb Dating of Calcite to Constrain Basinal Brine Flux Events: An Example from the Upper Midwest USA

    Rasbury, T.; Luczaj, J.

    2017-12-01

    Calcite forms in a variety of settings and can be the product of surface to deep basinal fluids. As such, this mineral can uniquely record details of the fluids responsible for its formation. The forms of calcium carbonates and their stratigraphic relationships from the thin section to the regional scale give important insights on pulses of fluids. A fundamental question is the age of such fluid pulses. While calcite excludes uranium (U) from its crystal structure, some is incorporated and depending on the U/Pb ratio, this provides an opportunity for radiometric dating. Calcite crystals of various sizes and crystal habits are found in Paleozoic carbonate rocks throughout the region from the western Michigan basin to the upper Mississippi valley. These are typically associated with Mississippi Valley-type (MVT) mineralization, including galena, sphalerite, and iron sulfides, but typically post-date the main MVT event. We have analyzed a variety of these calcites and find multiple generations of calcite, separated by tens of millions of years. The initial Pb isotope ratios are similar to the isotope ratios of nearby galena, strongly suggesting a genetic relationship. Our oldest ages are 200 Ma, and we find ages ranging into the Cenozoic. Based on the Paleozoic-hosted galena Pb-isotope isoscapes from the region, the fluids may have been sourced from both the Michigan and Illinois basins. An important and unanswered question is what would cause significant fluid movement out of the basins substantially after Appalachian orogenesis. Noble gas data from brines in the Michigan Basin have a mantle component and have been suggested to be responsible for recognized elevated temperatures across the basin (Ma et al., 2009). Multiple thermal events during the Paleozoic and Mesozoic eras may have an internal heat source related to reactivation of faults of the Keweenawan Rift system below the Michigan Basin. Perhaps a mantle heat source from below episodically fluxes into the

  10. Stochastic line motion and stochastic flux conservation for nonideal hydromagnetic models

    Eyink, Gregory L.

    2009-01-01

    We prove that smooth solutions of nonideal (viscous and resistive) incompressible magnetohydrodynamic (MHD) equations satisfy a stochastic law of flux conservation. This property implies that the magnetic flux through a surface is equal to the average of the magnetic fluxes through an ensemble of surfaces advected backward in time by the plasma velocity perturbed with a random white noise. Our result is an analog of the well-known Alfven theorem of ideal MHD and is valid for any value of the magnetic Prandtl number. A second stochastic conservation law is shown to hold at unit Prandtl number, a random version of the generalized Kelvin theorem derived by Bekenstein and Oron for ideal MHD. These stochastic conservation laws are not only shown to be consequences of the nonideal MHD equations but are proved in fact to be equivalent to those equations. We derive similar results for two more refined hydromagnetic models, Hall MHD and the two-fluid plasma model, still assuming incompressible velocities and isotropic transport coefficients. Finally, we use these results to discuss briefly the infinite-Reynolds-number limit of hydromagnetic turbulence and to support the conjecture that flux conservation remains stochastic in that limit.

  11. Evidence of Decay of Flux Ratio of Fe to Fe–Ni Line Features with ...

    2010-08-18

    Aug 18, 2010 ... measuring of the intensity and mean energy of the Fe and Fe–Ni line ... The instrumentation of the SLD payload, its in-flight calibration and operation ... reconnection process and also decays faster compared to many other ... measure vary over time and these factors mainly control the shape of the line. The.

  12. Zenith distribution and flux of atmospheric muons measured with the 5-line ANTARES detector

    Aguilar, J. A.; Albert, A.; Anton, G.; Anvar, S.; Ardid, M.; Jesus, A. C. Assis; Astraatmadja, T.; Aubertg, J. -J.; Auer, R.; Baret, B.; Basa, S.; Bazzotti, M.; Berting, V.; Biagi, S.; Bigongiari, C.; Bou-Cabo, M.; Bouwhuis, M. C.; Brown, A. M.; Brunnerg, J.; Busto, J.; Camarena, F.; Capone, A.; Carminati, G.; Carr, J.; Castel, D.; Castorina, E.; Cavasinni, V.; Cecchini, S.; Charvis, Ph.; Chiarusi, T.; Circella, M.; Coniglione, R.; Costantini, H.; Cottini, N.; Coyle, P.; Curtil, C.; De Bonis, G.; Decowski, M. P.; Dekeyser, I.; Deschamps, A.; Distefano, C.; Donzaud, C.; Dornic, D.; Drouhin, D.; Eberl, T.; Emanuele, U.; Ernenweing, J. -P.; Kalantar-Nayestanaki, N.; Kretschmer, W.; Loehner, H.

    2010-01-01

    The ANTARES high-energy neutrino telescope is a three-dimensional array of about 900 photomultipliers distributed over 12 mooring lines installed in the Mediterranean Sea. Between February and November 2007 it acquired data in a 5-line configuration. The zenith angular distribution of the

  13. Rhodium self-powered neutron detector as a suitable on-line thermal neutron flux monitor in BNCT treatments.

    Miller, Marcelo E; Sztejnberg, Manuel L; González, Sara J; Thorp, Silvia I; Longhino, Juan M; Estryk, Guillermo

    2011-12-01

    A rhodium self-powered neutron detector (Rh SPND) has been specifically developed by the Comisión Nacional de Energía Atómica (CNEA) of Argentina to measure locally and in real time thermal neutron fluxes in patients treated with boron neutron capture therapy (BNCT). In this work, the thermal and epithermal neutron response of the Rh SPND was evaluated by studying the detector response to two different reactor spectra. In addition, during clinical trials of the BNCT Project of the CNEA, on-line neutron flux measurements using the specially designed detector were assessed. The first calibration of the detector was done with the well-thermalized neutron spectrum of the CNEA RA-3 reactor thermal column. For this purpose, the reactor spectrum was approximated by a Maxwell-Boltzmann distribution in the thermal energy range. The second calibration was done at different positions along the central axis of a water-filled cylindrical phantom, placed in the mixed thermal-epithermal neutron beam of CNEA RA-6 reactor. In this latter case, the RA-6 neutron spectrum had been well characterized by both calculation and measurement, and it presented some marked differences with the ideal spectrum considered for SPND calibrations at RA-3. In addition, the RA-6 neutron spectrum varied with depth in the water phantom and thus the percentage of the epithermal contribution to the total neutron flux changed at each measurement location. Local (one point-position) and global (several points-positions) and thermal and mixed-field thermal neutron sensitivities were determined from these measurements. Thermal neutron flux was also measured during BNCT clinical trials within the irradiation fields incident on the patients. In order to achieve this, the detector was placed on patient's skin at dosimetric reference points for each one of the fields. System stability was adequate for this kind of measurement. Local mixed-field thermal neutron sensitivities and global thermal and mixed

  14. Rhodium self-powered neutron detector as a suitable on-line thermal neutron flux monitor in BNCT treatments

    Miller, Marcelo E.; Sztejnberg, Manuel L.; Gonzalez, Sara J.; Thorp, Silvia I.; Longhino, Juan M.; Estryk, Guillermo [Comision Nacional de Energia Atomica, Av. del Libertador 8250, Ciudad de Buenos Aires 1429 (Argentina); Comision Nacional de Energia Atomica, Av. del Libertador 8250, Ciudad de Buenos Aires 1429, Argentina and CONICET, Av. Rivadavia 1917, Ciudad de Buenos Aires 1033 (Argentina); Comision Nacional de Energia Atomica, Av. del Libertador 8250, Ciudad de Buenos Aires 1429 (Argentina)

    2011-12-15

    Purpose: A rhodium self-powered neutron detector (Rh SPND) has been specifically developed by the Comision Nacional de Energia Atomica (CNEA) of Argentina to measure locally and in real time thermal neutron fluxes in patients treated with boron neutron capture therapy (BNCT). In this work, the thermal and epithermal neutron response of the Rh SPND was evaluated by studying the detector response to two different reactor spectra. In addition, during clinical trials of the BNCT Project of the CNEA, on-line neutron flux measurements using the specially designed detector were assessed. Methods: The first calibration of the detector was done with the well-thermalized neutron spectrum of the CNEA RA-3 reactor thermal column. For this purpose, the reactor spectrum was approximated by a Maxwell-Boltzmann distribution in the thermal energy range. The second calibration was done at different positions along the central axis of a water-filled cylindrical phantom, placed in the mixed thermal-epithermal neutron beam of CNEA RA-6 reactor. In this latter case, the RA-6 neutron spectrum had been well characterized by both calculation and measurement, and it presented some marked differences with the ideal spectrum considered for SPND calibrations at RA-3. In addition, the RA-6 neutron spectrum varied with depth in the water phantom and thus the percentage of the epithermal contribution to the total neutron flux changed at each measurement location. Local (one point-position) and global (several points-positions) and thermal and mixed-field thermal neutron sensitivities were determined from these measurements. Thermal neutron flux was also measured during BNCT clinical trials within the irradiation fields incident on the patients. In order to achieve this, the detector was placed on patient's skin at dosimetric reference points for each one of the fields. System stability was adequate for this kind of measurement. Results: Local mixed-field thermal neutron sensitivities and

  15. Rhodium self-powered neutron detector as a suitable on-line thermal neutron flux monitor in BNCT treatments

    Miller, Marcelo E.; Sztejnberg, Manuel L.; Gonzalez, Sara J.; Thorp, Silvia I.; Longhino, Juan M.; Estryk, Guillermo

    2011-01-01

    Purpose: A rhodium self-powered neutron detector (Rh SPND) has been specifically developed by the Comision Nacional de Energia Atomica (CNEA) of Argentina to measure locally and in real time thermal neutron fluxes in patients treated with boron neutron capture therapy (BNCT). In this work, the thermal and epithermal neutron response of the Rh SPND was evaluated by studying the detector response to two different reactor spectra. In addition, during clinical trials of the BNCT Project of the CNEA, on-line neutron flux measurements using the specially designed detector were assessed. Methods: The first calibration of the detector was done with the well-thermalized neutron spectrum of the CNEA RA-3 reactor thermal column. For this purpose, the reactor spectrum was approximated by a Maxwell-Boltzmann distribution in the thermal energy range. The second calibration was done at different positions along the central axis of a water-filled cylindrical phantom, placed in the mixed thermal-epithermal neutron beam of CNEA RA-6 reactor. In this latter case, the RA-6 neutron spectrum had been well characterized by both calculation and measurement, and it presented some marked differences with the ideal spectrum considered for SPND calibrations at RA-3. In addition, the RA-6 neutron spectrum varied with depth in the water phantom and thus the percentage of the epithermal contribution to the total neutron flux changed at each measurement location. Local (one point-position) and global (several points-positions) and thermal and mixed-field thermal neutron sensitivities were determined from these measurements. Thermal neutron flux was also measured during BNCT clinical trials within the irradiation fields incident on the patients. In order to achieve this, the detector was placed on patient's skin at dosimetric reference points for each one of the fields. System stability was adequate for this kind of measurement. Results: Local mixed-field thermal neutron sensitivities and global

  16. An ecological paradox: high species diversity and low position of the upper forest line in the Andean Depression.

    Peters, Thorsten; Braeuning, Achim; Muenchow, Jannes; Richter, Michael

    2014-06-01

    Systematic investigations of the upper forest line (UFL) primarily concentrate on mid and high latitudes of the Northern Hemisphere, whereas studies of Neotropical UFLs are still fragmentary. This article outlines the extraordinary high tree diversity at the UFL within the Andean Depression and unravels the links between the comparatively low position of the local UFL, high tree-species diversity, and climate. On the basis of Gentry's rapid inventory methodology for the tropics, vegetation sampling was conducted at 12 UFL sites, and local climate (temperature, wind, precipitation, and soil moisture) was investigated at six sites. Monotypic forests dominated by Polylepis were only found at the higher located margins of the Andean Depression while the lower situated core areas were characterized by a species-rich forest, which lacked the elsewhere dominant tree-species Polylepis. In total, a remarkably high tree-species number of 255 tree species of 40 different plant families was found. Beta-diversity was also high with more than two complete species turnovers. A non-linear relationship between the floristic similarity of the investigated study sites and elevation was detected. Temperatures at the investigated study sites clearly exceeded 5.5°C, the postulated threshold value for the upper tree growth limit in the tropics. Instead, quasi-permanent trade winds, high precipitation amounts, and high soil water contents affect the local position of the UFL in a negative way. Interestingly, most of the above-mentioned factors are also contributing to the high species richness. The result is a combination of a clearly marked upper forest line depression combined with an extraordinary forest line complexity, which was an almost unknown paradox.

  17. Upper and lower solutions for BVPs on the half-line with variable coefficient and derivative depending nonlinearity

    S. Djebali

    2011-02-01

    Full Text Available This paper is concerned with a second-order nonlinear boundary value problem with a derivative depending nonlinearity and posed on the positive half-line. The derivative operator is time dependent. Upon a priori estimates and under a Nagumo growth condition, the Schauder's fixed point theorem combined with the method of upper and lower solutions on unbounded domains are used to prove existence of solutions. A uniqueness theorem is also obtained and some examples of application illustrate the obtained results.

  18. Effects of drugs in subtoxic concentrations on the metabolic fluxes in human hepatoma cell line Hep G2

    Niklas, Jens; Noor, Fozia; Heinzle, Elmar

    2009-01-01

    Commonly used cytotoxicity assays assess the toxicity of a compound by measuring certain parameters which directly or indirectly correlate to the viability of the cells. However, the effects of a given compound at concentrations considerably below EC 50 values are usually not evaluated. These subtoxic effects are difficult to identify but may eventually cause severe and costly long term problems such as idiosyncratic hepatotoxicity. We determined the toxicity of three hepatotoxic compounds, namely amiodarone, diclofenac and tacrine on the human hepatoma cell line Hep G2 using an online kinetic respiration assay and analysed the effects of subtoxic concentrations of these drugs on the cellular metabolism by using metabolic flux analysis. Several changes in the metabolism could be detected upon exposure to subtoxic concentrations of the test compounds. Upon exposure to diclofenac and tacrine an increase in the TCA-cycle activity was observed which could be a signature of an uncoupling of the oxidative phosphorylation. The results indicate that metabolic flux analysis could serve as an invaluable novel tool for the investigation of the effects of drugs. The described methodology enables tracking the toxicity of compounds dynamically using the respiration assay in a range of concentrations and the metabolic flux analysis permits interesting insights into the changes in the central metabolism of the cell upon exposure to drugs.

  19. Filtration of lager beer with microsieves: Flux, permeate haze and in-line microscope observations

    Kuiper, S.; van Rijn, C.J.M.; Nijdam, W.; Raspe, Onno; van Wolferen, Hendricus A.G.M.; Krijnen, Gijsbertus J.M.; Elwenspoek, Michael Curt

    2002-01-01

    Membrane fouling during filtration of lager beer with microsieves was studied through in-line microscope observations. It was observed that the main fouling was caused by micrometre-sized particles, presumably aggregated proteins. These particles formed flocks covering parts of the membrane surface.

  20. Rectification of leak from upper aluminium thermal shield cooling water inlet line of Cirus reactor

    Bhatnagar, Anil; Joshi, N.S.; Kharpate, A.V.; Marik, S.K.

    2006-01-01

    During 1994, a small water leak was observed from the upper aluminium thermal shield of Cirus reactor. Detailed investigations revealed that the leakage was from the weld joint of one of the 1 1/4 inch NB Sch. 80 coolant inlet pipes connected to the upper aluminium thermal shield. The location of the leak was identified by monitoring the stabilised water level in the vertical inlet pipe under stagnant condition. The exact location was identified by installing an inflatable seal arrangement inside the leaky pipe and inflating the seal at different elevations to isolate the leaky location and ensuring that the leak was completely stopped. This location was about 15 feet below the operating floor of the reactor. The pipe was visually inspected with the help of a fibre-scope to assess the condition of the inner surface. Eddy current testing was also carried out for volumetric examination. This revealed one more localised flaw on the outer surface little above the leaky joint. A hollow plug, with expandable rings, having C-shaped cross section at both the ends and a straight portion in the middle to cover the defective region, was developed and qualified in a mock-up station after extensive trials. In view of the site constraints, a flexible hollow link assembly was engineered, for installing the plug remotely. The inner surface of the pipe was cleaned using an emery brush and a deburring tool. The plug was then installed covering the leak area and the rings were expanded by remote tightening. The shield was hydro-tested satisfactorily. (author)

  1. Visualization of Sensory Neurons and Their Projections in an Upper Motor Neuron Reporter Line.

    Genç, Barış; Lagrimas, Amiko Krisa Bunag; Kuru, Pınar; Hess, Robert; Tu, Michael William; Menichella, Daniela Maria; Miller, Richard J; Paller, Amy S; Özdinler, P Hande

    2015-01-01

    Visualization of peripheral nervous system axons and cell bodies is important to understand their development, target recognition, and integration into complex circuitries. Numerous studies have used protein gene product (PGP) 9.5 [a.k.a. ubiquitin carboxy-terminal hydrolase L1 (UCHL1)] expression as a marker to label sensory neurons and their axons. Enhanced green fluorescent protein (eGFP) expression, under the control of UCHL1 promoter, is stable and long lasting in the UCHL1-eGFP reporter line. In addition to the genetic labeling of corticospinal motor neurons in the motor cortex and degeneration-resistant spinal motor neurons in the spinal cord, here we report that neurons of the peripheral nervous system are also fluorescently labeled in the UCHL1-eGFP reporter line. eGFP expression is turned on at embryonic ages and lasts through adulthood, allowing detailed studies of cell bodies, axons and target innervation patterns of all sensory neurons in vivo. In addition, visualization of both the sensory and the motor neurons in the same animal offers many advantages. In this report, we used UCHL1-eGFP reporter line in two different disease paradigms: diabetes and motor neuron disease. eGFP expression in sensory axons helped determine changes in epidermal nerve fiber density in a high-fat diet induced diabetes model. Our findings corroborate previous studies, and suggest that more than five months is required for significant skin denervation. Crossing UCHL1-eGFP with hSOD1G93A mice generated hSOD1G93A-UeGFP reporter line of amyotrophic lateral sclerosis, and revealed sensory nervous system defects, especially towards disease end-stage. Our studies not only emphasize the complexity of the disease in ALS, but also reveal that UCHL1-eGFP reporter line would be a valuable tool to visualize and study various aspects of sensory nervous system development and degeneration in the context of numerous diseases.

  2. Long-term nitrous oxide fluxes in annual and perennial agricultural and unmanaged ecosystems in the upper Midwest USA.

    Gelfand, Ilya; Shcherbak, Iurii; Millar, Neville; Kravchenko, Alexandra N; Robertson, G Philip

    2016-11-01

    Differences in soil nitrous oxide (N 2 O) fluxes among ecosystems are often difficult to evaluate and predict due to high spatial and temporal variabilities and few direct experimental comparisons. For 20 years, we measured N 2 O fluxes in 11 ecosystems in southwest Michigan USA: four annual grain crops (corn-soybean-wheat rotations) managed with conventional, no-till, reduced input, or biologically based/organic inputs; three perennial crops (alfalfa, poplar, and conifers); and four unmanaged ecosystems of different successional age including mature forest. Average N 2 O emissions were higher from annual grain and N-fixing cropping systems than from nonleguminous perennial cropping systems and were low across unmanaged ecosystems. Among annual cropping systems full-rotation fluxes were indistinguishable from one another but rotation phase mattered. For example, those systems with cover crops and reduced fertilizer N emitted more N 2 O during the corn and soybean phases, but during the wheat phase fluxes were ~40% lower. Likewise, no-till did not differ from conventional tillage over the entire rotation but reduced emissions ~20% in the wheat phase and increased emissions 30-80% in the corn and soybean phases. Greenhouse gas intensity for the annual crops (flux per unit yield) was lowest for soybeans produced under conventional management, while for the 11 other crop × management combinations intensities were similar to one another. Among the fertilized systems, emissions ranged from 0.30 to 1.33 kg N 2 O-N ha -1  yr -1 and were best predicted by IPCC Tier 1 and ΔEF emission factor approaches. Annual cumulative fluxes from perennial systems were best explained by soil NO3- pools (r 2  = 0.72) but not so for annual crops, where management differences overrode simple correlations. Daily soil N 2 O emissions were poorly predicted by any measured variables. Overall, long-term measurements reveal lower fluxes in nonlegume perennial vegetation and, for

  3. Improved Haptic Linear Lines for Better Movement Accuracy in Upper Limb Rehabilitation

    Joan De Boeck

    2012-01-01

    Full Text Available Force feedback has proven to be beneficial in the domain of robot-assisted rehabilitation. According to the patients' personal needs, the generated forces may either be used to assist, support, or oppose their movements. In our current research project, we focus onto the upper limb training for MS (multiple sclerosis and CVA (cerebrovascular accident patients, in which a basic building block to implement many rehabilitation exercises was found. This building block is a haptic linear path: a second-order continuous path, defined by a list of points in space. Earlier, different attempts have been investigated to realize haptic linear paths. In order to have a good training quality, it is important that the haptic simulation is continuous up to the second derivative while the patient is enforced to follow the path tightly, even when low or no guiding forces are provided. In this paper, we describe our best solution to these haptic linear paths, discuss the weaknesses found in practice, and propose and validate an improvement.

  4. Parameter investigation with line-implicit lower-upper symmetric Gauss-Seidel on 3D stretched grids

    Otero, Evelyn; Eliasson, Peter

    2015-03-01

    An implicit lower-upper symmetric Gauss-Seidel (LU-SGS) solver has been implemented as a multigrid smoother combined with a line-implicit method as an acceleration technique for Reynolds-averaged Navier-Stokes (RANS) simulation on stretched meshes. The computational fluid dynamics code concerned is Edge, an edge-based finite volume Navier-Stokes flow solver for structured and unstructured grids. The paper focuses on the investigation of the parameters related to our novel line-implicit LU-SGS solver for convergence acceleration on 3D RANS meshes. The LU-SGS parameters are defined as the Courant-Friedrichs-Lewy number, the left-hand side dissipation, and the convergence of iterative solution of the linear problem arising from the linearisation of the implicit scheme. The influence of these parameters on the overall convergence is presented and default values are defined for maximum convergence acceleration. The optimised settings are applied to 3D RANS computations for comparison with explicit and line-implicit Runge-Kutta smoothing. For most of the cases, a computing time acceleration of the order of 2 is found depending on the mesh type, namely the boundary layer and the magnitude of residual reduction.

  5. @u234@@Th scavenging and particle export fluxes from the upper 100 m of the Arabian Sea

    Sarin, M.M.; Rengarajan, R.; Ramaswamy, V.

    for the upper 100 m yields a mean scavenging residence time of ~k30 days and a removal rate of ~k 3400 dpm m@u-2@@ d@u-1@@ for @u234@@Th, from dissolved to particulate phases. The deficiency of total @u234@@Th (dissolved + particulate) relative to @u238@@U...

  6. SREM - WRS system module number 3348 for calculating the removal flux due to point, line or disc sources

    Grimstone, M.J.

    1978-06-01

    The WRS Modular Programming System has been developed as a means by which programmes may be more efficiently constructed, maintained and modified. In this system a module is a self-contained unit typically composed of one or more Fortran routines, and a programme is constructed from a number of such modules. This report describes one WRS module, the function of which is to calculate the uncollided flux and first-collision source from a disc source in a slab geometry system, a line source at the centre of a cylindrical system or a point source at the centre of a spherical system. The information given in this manual is of use both to the programmer wishing to incorporate the module in a programme, and to the user of such a programme. (author)

  7. Abrikosov flux-lines in two-band superconductors with mixed dimensionality

    Tanaka, K; Eschrig, M

    2009-01-01

    We study vortex structure in a two-band superconductor, in which one band is ballistic and quasi-two-dimensional (2D), and the other is diffusive and three-dimensional (3D). A circular cell approximation of the vortex lattice within the quasiclassical theory of superconductivity is applied to a recently developed model appropriate for such a two-band system (Tanaka et al 2006 Phys. Rev. B 73 220501(R); Tanaka et al 2007 Phys. Rev. B 75 214512). We assume that superconductivity in the 3D diffusive band is 'weak', i.e. mostly induced, as is the case in MgB 2 . Hybridization with the 'weak' 3D diffusive band has significant and intriguing influence on the electronic structure of the 'strong' 2D ballistic band. In particular, the Coulomb repulsion and the diffusivity in the 'weak' band enhance suppression of the order parameter and enlargement of the vortex core by magnetic field in the 'strong' band, resulting in reduced critical temperature and field. Moreover, increased diffusivity in the 'weak' band can result in an upward curvature of the upper critical field near the transition temperature. A particularly interesting feature found in our model is the appearance of additional bound states at the gap edge in the 'strong' ballistic band, which are absent in the single-band case. Furthermore, coupling with the 'weak' diffusive band leads to reduced bandgaps and van Hove singularities of energy bands of the vortex lattice in the 'strong' ballistic band. We find these intriguing features for parameter values appropriate for MgB 2 .

  8. Stellar model chromospheres. X. High-resolution, absolute flux profiles of the Ca II H and K lines in stars of sepctral types FO--M2

    Linsky, J.L.; Worden, S.P.; McClintock, V.; Robertson, R.M.

    1979-01-01

    We present 120 mA resolution spectra of the cores and wings of the Ca II H and K lines in 43 stars covering a wide range of spectral type and luminosity class. These spectra were obtained with the KPNO 4 m echelle spectrograph and blue image tube, and are calibrated in absolute suface flux units using Willstrop's narrow-band photometry and the Barnes and Evans relations for stellar angular diameters. We estimate an uncertainty of +- 15% in our flux scales. We derive chromospheric radiative loss rates in H and K lines, and discuss trenfs in these loss rates with effective temperature for dwarfs, giants and supergiants. We compare these loss rates with similar rates for the Mg II h and k lines, and discuss the doublet line ratios for H and K. The monochromatic surface fluxes for different features in the H and K lines are presented. From the surface fluxes at K 1 we derived the radiation temperature T/sub R/(K 1 ). The T/sub R/(K 1 )/T/sub eff/ ratio is lower in giants than in dwarfs, as predicted by partial redistribution calculations, and this ratio appears to be an empirical age indicator among dwarfs. Asymmetries in the K line profile provide evidence for a solar-type supergranulation flow pattern in F5--K5 dwarfs and perhaps aslo in G and early K supergiants. Measurements of line widths at H 1 , K 1 , and K 2 are presented, together with FWHM data for the H and K lines. We find rough agreement between the measured K 1 widths and the gravity and chromospheric heating rate dependences in the scaling law proposed by Ayeres. Finally, we present data on emission lines in the wings of H and K, and discuss chromospheric radiative loss rates in the Hepsilon line compared with loss rates in the H and K lines

  9. On-Line Fission Gas Release Monitoring System in the High Flux Reactor Petten

    Laurie, M.; Fuetterer, M. A.; Appelman, K.H.; Lapetite, J.-M.; Marmier, A.; Knol, S.; Best, J.

    2013-06-01

    For HTR fuel irradiation tests in the HFR Petten a specific installation was designed and installed dubbed the 'Sweep Loop Facility' (SLF). The SLF is tasked with three functions, namely temperature control by gas mixture technique, surveillance of safety parameters (temperature, pressure, radioactivity etc.) and analysis of fission gas release for three individual capsules in two separate experimental rigs. The SLF enables continuous and independent surveillance of all gas circuits. The release of volatile fission products (FP) from the in-pile experiments is monitored by continuous gas purging. The fractional release of these FP, defined as the ratio between release rate of a gaseous fission isotope (measured) to its instantaneous birth rate (calculated), is a licensing-relevant test for HTR fuel. The developed gamma spectrometry station allows for higher measurement frequencies, thus enabling follow-up of rapid and massive release transients. The designed stand-alone system was tested and fully used through the final irradiation period of the HFR-EU1 experiment which was terminated on 18 February 2010. Its robustness allowed the set up to be used as extra safety instrumentation. This paper describes the gas activity measurement technique based on HPGe gamma spectrometry and illustrates how qualitative and quantitative analysis of volatile FP can be performed on-line. (authors)

  10. Flux-line cutting in granular high-T{sub c} and semi-reversible classical type-II superconductors

    Perez-Rodriguez, F. [Instituto de Fisica, Universidad Autonoma de Puebla, Puebla, Pue (Mexico); LeBlanc, M.A.R.; Gandolfini, G. [Department of Physics, University of Ottawa (Canada)

    2001-06-01

    The magnetic responses of granular (NdBa{sub 2}Cu{sub 3}O{sub 7-x} and YBa{sub 2}Cu{sub 3}O{sub 7-x}) and monolithic (PbIn) superconducting plates, cooled in a fixed magnetic field H{sub z} parallel to their plane and, later, subjected to cycles of a transverse magnetic field H{sub y} with an amplitude H{sub y,max}>H{sub z}, are investigated both experimentally and theoretically. Magnetization curves, generated as H{sub y} with H{sub z} constant applied and of the order of the full penetration field H{sub p}, are interpreted by employing two competing models (the double critical-state model and the two-velocity hydrodynamic model) for describing flux-line cutting effects on the magnetic behaviour of superconductors. Both models qualitatively and semi-quantitatively reproduce the experimental curves. Unlike the double critical-state model, the two-velocity hydrodynamic approach predicts the appearance of zones with homogeneous magnitude of the magnetic induction B at relatively small values of H{sub y} as vertical bar H{sub y} vertical bar is increased. However the effect of these zones is not appreciable since they disappear when vertical bar H{sub y} vertical bar reaches a sufficiently large value: vertical bar H{sub y} vertical bar > or {approx} H{sub z} {approx} H{sub p}. (author)

  11. Melting of the flux line lattice observed by specific heat experiments in YBa2Cu3O7-δ

    Roulin, M.; Junod, A.; Erb, A.; Walker, E.

    1996-01-01

    High resolution adiabatic specific heat experiments on YBa 2 Cu 3 O 7-δ (0≤δ≤0.05) are performed in magnetic fields from 0 to 14 T (B parallel c and B perpendicular c). In a 0.3 gram, twinned crystal with strong pinning, a step is consistently observed at the melting temperature T m of the vortex solid up to a critical point that depends on δ. The field B m and step temperature T m obey the relation B m =B m0 (δ)(1-T m /T c ) ∼4/3 . The anisotropy of B m and that of the upper critical field B c2 are found to be equal. Alternatively, in a 18 mg, twinned crystal of high purity with low pinning, first-order-like specific heat peaks are observed on the melting line from 8 to 14 T. The entropy under these peaks is ∼0.5 k B /vortex/bilayer. These characteristic features are attributed to the melting of a vortex glass in the former case and that of a vortex lattice in the latter case

  12. BOOSTING LY α   AND He ii λ 1640 LINE FLUXES FROM POPULATION III GALAXIES: STOCHASTIC IMF SAMPLING AND DEPARTURES FROM CASE-B

    Mas-Ribas, Lluís; Dijkstra, Mark; Forero-Romero, Jaime E.

    2016-01-01

    We revisit calculations of nebular hydrogen Ly α and He ii λ 1640 line strengths for Population III (Pop III) galaxies, undergoing continuous, and bursts of, star formation. We focus on initial mass functions (IMFs) motivated by recent theoretical studies, which generally span a lower range of stellar masses than earlier works. We also account for case-B departures and the stochastic sampling of the IMF. In agreement with previous work, we find that departures from case-B can enhance the Ly α flux by a factor of a few, but we argue that this enhancement is driven mainly by collisional excitation and ionization, and not due to photoionization from the n  = 2 state of atomic hydrogen. The increased sensitivity of the Ly α flux to the high-energy end of the galaxy spectrum makes it more subject to stochastic sampling of the IMF. The latter introduces a dispersion in the predicted nebular line fluxes around the deterministic value by as much as a factor of ∼4. In contrast, the stochastic sampling of the IMF has less impact on the emerging Lyman Werner photon flux. When case-B departures and stochasticity effects are combined, nebular line emission from Pop III galaxies can be up to one order of magnitude brighter than predicted by “standard” calculations that do not include these effects. This enhances the prospects for detection with future facilities such as the James Webb Space Telescope and large, ground-based telescopes.

  13. Boosting Lyα and He II λ1640 Line Fluxes from Population III Galaxies: Stochastic IMF Sampling and Departures from Case-B

    Mas-Ribas, Lluís; Dijkstra, Mark; Forero-Romero, Jaime E.

    2016-12-01

    We revisit calculations of nebular hydrogen Lyα and He II λ1640 line strengths for Population III (Pop III) galaxies, undergoing continuous, and bursts of, star formation. We focus on initial mass functions (IMFs) motivated by recent theoretical studies, which generally span a lower range of stellar masses than earlier works. We also account for case-B departures and the stochastic sampling of the IMF. In agreement with previous work, we find that departures from case-B can enhance the Lyα flux by a factor of a few, but we argue that this enhancement is driven mainly by collisional excitation and ionization, and not due to photoionization from the n = 2 state of atomic hydrogen. The increased sensitivity of the Lyα flux to the high-energy end of the galaxy spectrum makes it more subject to stochastic sampling of the IMF. The latter introduces a dispersion in the predicted nebular line fluxes around the deterministic value by as much as a factor of ˜4. In contrast, the stochastic sampling of the IMF has less impact on the emerging Lyman Werner photon flux. When case-B departures and stochasticity effects are combined, nebular line emission from Pop III galaxies can be up to one order of magnitude brighter than predicted by “standard” calculations that do not include these effects. This enhances the prospects for detection with future facilities such as the James Webb Space Telescope and large, ground-based telescopes.

  14. Reclosing operation characteristics of the flux-coupling type SFCL in a single-line-to ground fault

    Jung, B.I.; Cho, Y.S.; Choi, H.S.; Ha, K.H.; Choi, S.G.; Chul, D.C.; Sung, T.H.

    2011-01-01

    The recloser that is used in distribution systems is a relay system that behaves sequentially to protect power systems from transient and continuous faults. This reclosing operation of the recloser can improve the reliability and stability of the power supply. For cooperation with this recloser, the superconducting fault current limiter (SFCL) must properly perform the reclosing operation. This paper analyzed the reclosing operation characteristics of the three-phase flux-coupling type SFCL in the event of a ground fault. The fault current limiting characteristics according to the changing number of turns of the primary and secondary coils were examined. As the number of turns of the first coil increased, the first maximum fault current decreased. Furthermore, the voltage of the quenched superconducting element also decreased. This means that the power burden of the superconducting element decreases based on the increasing number of turns of the primary coil. The fault current limiting characteristic of the SFCL according to the reclosing time limited the fault current within a 0.5 cycles (8 ms), which is shorter than the closing time of the recloser. In other words, the superconducting element returned to the superconducting state before the second fault and normally performed the fault current limiting operation. If the SFCL did not recover before the recloser reclosing time, the normal current that was flowing in the transmission line after the recovery of the SFCL from the fault would have been limited and would have caused losses. Therefore, the fast recovery time of a SFCL is critical to its cooperation with the protection system.

  15. Reclosing operation characteristics of the flux-coupling type SFCL in a single-line-to ground fault

    Jung, B. I.; Cho, Y. S.; Choi, H. S.; Ha, K. H.; Choi, S. G.; Chul, D. C.; Sung, T. H.

    2011-11-01

    The recloser that is used in distribution systems is a relay system that behaves sequentially to protect power systems from transient and continuous faults. This reclosing operation of the recloser can improve the reliability and stability of the power supply. For cooperation with this recloser, the superconducting fault current limiter (SFCL) must properly perform the reclosing operation. This paper analyzed the reclosing operation characteristics of the three-phase flux-coupling type SFCL in the event of a ground fault. The fault current limiting characteristics according to the changing number of turns of the primary and secondary coils were examined. As the number of turns of the first coil increased, the first maximum fault current decreased. Furthermore, the voltage of the quenched superconducting element also decreased. This means that the power burden of the superconducting element decreases based on the increasing number of turns of the primary coil. The fault current limiting characteristic of the SFCL according to the reclosing time limited the fault current within a 0.5 cycles (8 ms), which is shorter than the closing time of the recloser. In other words, the superconducting element returned to the superconducting state before the second fault and normally performed the fault current limiting operation. If the SFCL did not recover before the recloser reclosing time, the normal current that was flowing in the transmission line after the recovery of the SFCL from the fault would have been limited and would have caused losses. Therefore, the fast recovery time of a SFCL is critical to its cooperation with the protection system.

  16. Joint estimation of the fast and thermal components of a high neutron flux with a two on-line detector system

    Filliatre, P.; Oriol, L.; Jammes, C.; Vermeeren, L.

    2009-01-01

    A fission chamber with a 242 Pu deposit is the best suited detector for on-line measurements of the fast component of a high neutron flux (∼10 14 ncm -2 s -1 or more) with a significant thermal component. To get the fast flux, it is, however, necessary to subtract the contribution of the thermal neutrons, which increases with fluence because of the evolution of the isotopic content of the deposit. This paper presents an algorithm that permits, thanks to measurements provided by a 242 Pu fission chamber and a detector for thermal neutrons, to estimate the thermal and the fast flux at any time. An implementation allows to test it with simulated data.

  17. Joint estimation of the fast and thermal components of a high neutron flux with a two on-line detector system

    Filliatre, P. [CEA, DEN, SPEx/LDCI, F-13108 Saint-Paul-lez-Durance (France); Laboratoire Commun d' Instrumentation CEA-SCK-CEN (France)], E-mail: philippe.filliatre@cea.fr; Oriol, L.; Jammes, C. [CEA, DEN, SPEx/LDCI, F-13108 Saint-Paul-lez-Durance (France); Laboratoire Commun d' Instrumentation CEA-SCK-CEN (France); Vermeeren, L. [SCK-CEN, Boeretang 200, B-2400 Mol (Belgium); Laboratoire Commun d' Instrumentation CEA-SCK-CEN (France)

    2009-05-21

    A fission chamber with a {sup 242}Pu deposit is the best suited detector for on-line measurements of the fast component of a high neutron flux ({approx}10{sup 14}ncm{sup -2}s{sup -1} or more) with a significant thermal component. To get the fast flux, it is, however, necessary to subtract the contribution of the thermal neutrons, which increases with fluence because of the evolution of the isotopic content of the deposit. This paper presents an algorithm that permits, thanks to measurements provided by a {sup 242}Pu fission chamber and a detector for thermal neutrons, to estimate the thermal and the fast flux at any time. An implementation allows to test it with simulated data.

  18. How the macroscopic current correlates with the microscopic flux-line distribution in a type-II superconductor: an experimental study

    Hecher, Johannes; Zehetmayer, Martin; Weber, Harald W

    2014-01-01

    We present a study of the real-space flux-line lattice (FLL) of pristine and neutron irradiated conventional type-II superconductors using scanning tunnelling microscopy. Our work is focused on the magnetic field range, where the critical current density shows a second peak as a result of neutron irradiation. Scanning tunnelling microscopy images, including more than 2000 flux lines, are used to evaluate various microscopic parameters describing the disorder of the FLL, such as the defect density, the nearest neighbour distances and correlation functions. These parameters are compared with the macroscopic critical current density of the samples. The results show a direct correlation of the micro- and macroscopic properties. We observe a clear transition from an ordered to a disordered lattice at the onset of the second peak. Moreover, we discuss the defects of the FLL and their accumulation to large clusters in the second peak region. (papers)

  19. Pinning in the flux-line-cutting regime of Bi 2Sr 2Ca 1Cu 2O 8 single crystals at high field

    D'Anna, G.; André, M.-O.; Indenbom, M. V.; Benoit, W.

    1994-09-01

    Using a low-frequency torsion pendulum we show that in a Bi 2Sr 2Ca 1Cu 2O 8 single crystal the irreversibility line Birr( T) is frequency dependent down to 10 -5 Hz in the high-field regime. The activation energy has a logarithmic field dependence, U0( B)= U∗ 1n( B∗/ B). A microscopic model for flux-line-cutting and pancake collision yields quantitative expressions for U0 and for Birr( T)= B∗ exp(- T/T∗), which reproduce the experimental data very well.

  20. Anatomy of Forehead, Glabellar, Nasal and Orbital Muscles, and Their Correlation with Distinctive Patterns of Skin Lines on the Upper Third of the Face: Reviewing Concepts.

    Abramo, Antonio Carlos; Do Amaral, Thiago Paoliello Alves; Lessio, Bruno Pierotti; De Lima, Germano Andrighetto

    2016-12-01

    The purpose of this study is to establish a relationship between the skin lines on the upper third of the face in cadavers, which represent the muscle activity in life and the skin lines achieved by voluntary contraction of the forehead, glabellar, and orbital muscles in patients. Anatomical dissection of fresh cadavers was performed in 20 fresh cadavers, 11 females and 9 males, with ages ranging from 53 to 77 years. Subcutaneous dissection identified the muscle shape and the continuity of the fibers of the eyebrow elevator and depress muscles. Subgaleal dissection identified the cutaneous insertions of the muscles. They were correlated with skin lines on the upper third of the face of the cadavers that represent the muscle activity in life. Voluntary contraction was performed by 20 voluntary patients, 13 females and 7 males, with ages ranging from 35 to 62 years. Distinct patterns of skin lines on the forehead, glabellar and orbital areas, and eyebrow displacement were identified. The frontalis exhibited four anatomical shapes with four different patterns of horizontal parallel lines on the forehead skin. The corrugator supercilii showed three shapes of muscles creating six patterns of vertical glabellar lines, three symmetrical and three asymmetrical. The orbicularis oculi and procerus had single patterns. The skin lines exhibited in voluntary contraction of the upper third of the face in patients showed the same patterns of the skin lines achieved in cadavers. Skin lines in cadavers, which are the expression of the muscle activity in life, were similar to those achieved in the voluntary contraction of patients, allowing us to assert that the muscle patterns of patients were similar to those identified in cadavers. This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies

  1. Metabolic flux rearrangement in the amino acid metabolism reduces ammonia stress in the α1-antitrypsin producing human AGE1.HN cell line.

    Priesnitz, Christian; Niklas, Jens; Rose, Thomas; Sandig, Volker; Heinzle, Elmar

    2012-03-01

    This study focused on metabolic changes in the neuronal human cell line AGE1.HN upon increased ammonia stress. Batch cultivations of α(1)-antitrypsin (A1AT) producing AGE1.HN cells were carried out in media with initial ammonia concentrations ranging from 0mM to 5mM. Growth, A1AT production, metabolite dynamics and finally metabolic fluxes calculated by metabolite balancing were compared. Growth and A1AT production decreased with increasing ammonia concentration. The maximum A1AT concentration decreased from 0.63g/l to 0.51g/l. Central energy metabolism remained relatively unaffected exhibiting only slightly increased glycolytic flux at high initial ammonia concentration in the medium. However, the amino acid metabolism was significantly changed. Fluxes through transaminases involved in amino acid degradation were reduced concurrently with a reduced uptake of amino acids. On the other hand fluxes through transaminases working in the direction of amino acid synthesis, i.e., alanine and phosphoserine, were increased leading to increased storage of excess nitrogen in extracellular alanine and serine. Glutamate dehydrogenase flux was reversed increasingly fixing free ammonia with increasing ammonia concentration. Urea production additionally observed was associated with arginine uptake by the cells and did not increase at high ammonia stress. It was therefore not used as nitrogen sink to remove excess ammonia. The results indicate that the AGE1.HN cell line can adapt to ammonia concentrations usually present during the cultivation process to a large extent by changing metabolism but with slightly reduced A1AT production and growth. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Laboratory toxicity and benthic invertebrate field colonization of Upper Columbia River sediments: finding adverse effects using multiple lines of evidence.

    Fairchild, J F; Kemble, N E; Allert, A L; Brumbaugh, W G; Ingersoll, C G; Dowling, B; Gruenenfelder, C; Roland, J L

    2012-07-01

    From 1930 to 1995, the Upper Columbia River (UCR) of northeast Washington State received approximately 12 million metric tons of smelter slag and associated effluents from a large smelter facility located in Trail, British Columbia, approximately 10 km north of the United States-Canadian border. Studies conducted during the past two decades have demonstrated the presence of toxic concentrations of heavy metals in slag-based sandy sediments, including cadmium, copper, zinc, and lead in the UCR area as well as the downstream reservoir portion of Lake Roosevelt. We conducted standardized whole-sediment toxicity tests with the amphipod Hyalella azteca (28-day) and the midge Chironomus dilutus (10-day) on 11 samples, including both UCR and study-specific reference sediments. Metal concentrations in sediments were modeled for potential toxicity using three approaches: (1) probable effects quotients (PEQs) based on total recoverable metals (TRMs) and simultaneously extracted metals (SEMs); (2) SEMs corrected for acid-volatile sulfides (AVS; i.e., ∑SEM - AVS); and (3) ∑SEM - AVS normalized to the fractional organic carbon (f(oc)) (i.e., ∑SEM - AVS/f(oc)). The most highly metal-contaminated sample (∑PEQ(TRM) = 132; ∑PEQ(SEM) = 54; ∑SEM - AVS = 323; and ∑SEM - AVS/(foc) = 64,600 umol/g) from the UCR was dominated by weathered slag sediment particles and resulted in 80% mortality and 94% decrease in biomass of amphipods; in addition, this sample significantly decreased growth of midge by 10%. The traditional ∑AVS - SEM, uncorrected for organic carbon, was the most accurate approach for estimating the effects of metals in the UCR. Treatment of the toxic slag sediment with 20% Resinex SIR-300 metal-chelating resin significantly decreased the toxicity of the sample. Samples ∑SEM - AVS > 244 was not toxic to amphipods or midge in laboratory testing, indicating that this value may be an approximate threshold for effects in the UCR. In situ benthic invertebrate

  3. Implantable self-powered detector for on-line determination of neutron flux in patients during NCT treatment.

    Miller, M E; Mariani, L E; Gonçalves-Carralves, M L Sztejnberg; Skumanic, M; Thorp, S I

    2004-11-01

    A novel system to determine thermal neutron flux in real time during NCT treatments was developed in the National Atomic Energy Commission of Argentina. The system is based on a special self-powered detector that can be implanted in patients owing to its small size and biocompatibility. High voltage is not required to operate this kind of detectors, which is a considerable advantage in terms of medical uses. By choosing the appropriate materials, it was possible to obtain a prototype with thermal neutron sensitivity providing for an adequate signal level in typical NCT thermal fluxes. It was also possible to minimize gamma response in order to neglect its contribution.

  4. Implantable self-powered detector for on-line determination of neutron flux in patients during NCT treatment

    Miller, M.E. E-mail: miller@cae.cnea.gov.ar; Mariani, L.E.; Sztejnberg Goncalves-Carralves, M.L.; Skumanic, M.; Thorp, S.I

    2004-11-01

    A novel system to determine thermal neutron flux in real time during NCT treatments was developed in the National Atomic Energy Commission of Argentina. The system is based on a special self-powered detector that can be implanted in patients owing to its small size and biocompatibility. High voltage is not required to operate this kind of detectors, which is a considerable advantage in terms of medical uses. By choosing the appropriate materials, it was possible to obtain a prototype with thermal neutron sensitivity providing for an adequate signal level in typical NCT thermal fluxes. It was also possible to minimize gamma response in order to neglect its contribution.

  5. Critical current density, irreversibility line, and flux creep activation energy in silver-sheathed Bi2Sr2Ca2Cu3Ox superconducting tapes

    Shi, D.; Wang, Z.; Sengupta, S.; Smith, M.; Goodrich, L.F.; Dou, S.X.; Liu, H.K.; Guo, Y.C.

    1992-08-01

    Transport data, magnetic hysteresis and flux creep activation energy experimental results are presented for silver-sheathed high-T c Bi 2 Sr 2 Ca 2 Cu 3 O x superconducting tapes. The 110 K superconducting phase was formed by lead doping in a Bi-Sr-Ca-Cu-0 system. The transport critical current density was measured at 4.0 K to be 0.7 x 10 5 A/cm 2 (the corresponding critical current is 74 A) at zero field and 1.6 x 10 4 A/cm 2 at 12 T for H parallel ab. Excellent grain alignment in the a-b plane was achieved by a short-melting method, which considerably improved the critical current density and irreversibility line. Flux creep activation energy as a function of current is obtained based on the magnetic relaxation measurements

  6. Upper limits on the 21 cm power spectrum at z = 5.9 from quasar absorption line spectroscopy

    Pober, Jonathan C.; Greig, Bradley; Mesinger, Andrei

    2016-11-01

    We present upper limits on the 21 cm power spectrum at z = 5.9 calculated from the model-independent limit on the neutral fraction of the intergalactic medium of x_{H I} chain Monte Carlo Epoch of Reionization analysis code, we explore the probability distribution of 21 cm power spectra consistent with this constraint on the neutral fraction. We present 99 per cent confidence upper limits of Δ2(k) limit dependent on the sampled k mode. This limit can be used as a null test for 21 cm experiments: a detection of power at z = 5.9 in excess of this value is highly suggestive of residual foreground contamination or other systematic errors affecting the analysis.

  7. LINES

    Minas Bakalchev

    2015-10-01

    Full Text Available The perception of elements in a system often creates their interdependence, interconditionality, and suppression. The lines from a basic geometrical element have become the model of a reductive world based on isolation according to certain criteria such as function, structure, and social organization. Their traces are experienced in the contemporary world as fragments or ruins of a system of domination of an assumed hierarchical unity. How can one release oneself from such dependence or determinism? How can the lines become less “systematic” and forms more autonomous, and less reductive? How is a form released from modernistic determinism on the new controversial ground? How can these elements or forms of representation become forms of action in the present complex world? In this paper, the meaning of lines through the ideas of Le Corbusier, Leonidov, Picasso, and Hitchcock is presented. Spatial research was made through a series of examples arising from the projects of the architectural studio “Residential Transformations”, which was a backbone for mapping the possibilities ranging from playfulness to exactness, as tactics of transformation in the different contexts of the contemporary world.

  8. Self-Powered Neutron Detector Qualification for Absolute On-Line In-Pile Neutron Flux Measurements in BR2

    Vermeeren, L.; Wéber, M.

    2003-06-01

    A set of ten Self-Powered Neutron Detectors with Co, Rh and Ag emitters has been irradiated in several channels of the BR2 research reactor at SCK•CEN aiming at a comparison of their performance as thermal neutron flux detectors under various conditions. To allow for a correct interpretation of their signals, all detector sensitivity contributions (prompt and delayed) were calculated using a dedicated Monte Carlo model. The various contributions were also measured separately; the agreement between calculated and experimental data, including data from activation dosimetry, was excellent. Detailed neutron flux profiles were obtained from the SPND data, after correction for the finite detector lengths and for the slow response of delayed SPNDs.

  9. Frequency and amplitude response of the flux-line lattice to mechanical perturbation in ceramic YBa 2Cu 3O 7

    Luzuriaga, J.; André, M.-O.; Benoit, W.

    1992-10-01

    The mechanical response of the flux-line lattice has been measured with a low-frequency forced pendulum in ceramic YBa 2Cu 3O 7. A dissipation peak observed in temperature sweeps is frequency-independent between 1 mHz and 5 Hz. Dissipation depends strongly on applied torque, and for fixed temperatures this dependence is well fitted by a rheological model of extended dry friction. If the model is extended to take account of thermal activation, however, it does not agree with the measured frequency independence, which is hard to explain within simple models of thermal activation.

  10. On-line iron loss resistance identification by a state observer for rotor-flux-oriented control of induction motor

    Barrera, Pablo M. de la; Bossio, Guillermo R.; Solsona, Jorge A.; Garcia, Guillermo O.

    2008-01-01

    A rotor flux state observer considering iron loss, for an Induction Motor (IM), is proposed. The aim of this proposal is to avoid detuning caused by the IM iron loss on a field-oriented control (FOC). An adaptive scheme for the K Fe , a parameter that represents the IM iron loss, is also proposed. The main objective of this scheme is to improve the dynamic response of control by compensating the variations of iron losses due to possible variations in the stator core characteristics. Simulation results demonstrated that the observer and the adaptive scheme showed a good performance fulfilling then the objectives

  11. Noninvasive Sampling of Mucosal Lining Fluid for the Quantification of In Vivo Upper Airway Immune-mediator Levels

    Wolsk, Helene Mygind; Chawes, Bo L.; Thorsen, Jonathan

    2017-01-01

    (often used by other techniques). The mucosal lining fluid is sampled on a strip of filter paper placed at the anterior part of the inferior turbinate and left for 2 min of absorption. Analytes are eluted from the filter papers, and the extracted protein-based eluates are analyzed...

  12. Control of grid integrated voltage source converters under unbalanced conditions: development of an on-line frequency-adaptive virtual flux-based approach

    Suul, Jon Are

    2012-03-15

    Three-Phase Voltage Source Converters (VSCs) are finding widespread applications in grid integrated power conversion systems. The control systems of such VSCs are in an increasing number of these applications required to operate during voltage disturbances and unbalanced conditions. Control systems designed for grid side voltagesensor-less operation are at the same time becoming attractive due to the continuous drive for cost reduction and increased reliability of VSCs, but are not commonly applied for operation during unbalanced conditions. Methods for voltage-sensor-less grid synchronization and control of VSCs under unbalanced grid voltage conditions will therefore be the main focus of this Thesis. Estimation methods based on the concept of Virtual Flux, considering the integral of the converter voltage in analogy to the flux of an electric machine, are among the simplest and most well known techniques for achieving voltage-sensor-less grid synchronization. Most of the established techniques for Virtual Flux estimation are, however, either sensitive to grid frequency variations or they are not easily adaptable for operation under unbalanced grid voltage conditions. This Thesis addresses both these issues by proposing a simple approach for Virtual Flux estimation by utilizing a frequency-adaptive filter based on a Second Order Generalized Integrator (SOGI). The proposed approach can be used to achieve on-line frequency-adaptive varieties of conventional strategies for Virtual Flux estimation. The main advantage is, however, that the SOGI-based Virtual Flux estimation can be arranged in a structure that achieves inherent symmetrical component sequence separation under unbalanced conditions. The proposed method for Virtual Flux estimation can be used as a general basis for voltage-sensor-less grid synchronization and control during unbalanced conditions. In this Thesis, the estimated Virtual Flux signals are used to develop a flexible strategy for control of active

  13. Flux line lattice melting transition in YBa2Cu3O6.94 observed in specific heat experiments

    Roulin, M.; Junod, A.; Walker, E.

    1996-01-01

    When a magnetic field penetrates a type II superconductor, it forms a lattice of thin quantized filaments called magnetic vortices. Resistance, magnetization, and neutron diffraction experiments have shown that the vortex lattice of high-temperature superconductors can melt along a line in the field-temperature plane. The calorimetric signature of melting on this line was observed in a high-accuracy adiabatic specific heat experiment performed on YBa 2 Cu 3 O 6.94 . The specific heat of the vortex liquid was greater than that of the vortex solid. 17 refs., 3 figs

  14. Graphene oxide quantum dots disrupt autophagic flux by inhibiting lysosome activity in GC-2 and TM4 cell lines

    Ji, Xiaoli; Xu, Bo; Yao, Mengmeng; Mao, Zhilei; Zhang, Yuqing; Xu, Guofeng; Tang, Qiusha; Wang, Xinru; Xia, Yankai

    2016-01-01

    Graphene oxide quantum dots (GOQDs) have broad application prospects in many areas including bioimaging, drug delivery, DNA cleavage system, sensors and photocatalyst. Recently, increasing concerns have been raised about their biocompatibility, but studies about the effects of GOQDs on male reproductive system are still lacking. In this work, we explored the effects and molecular mechanisms of GOQDs on GC-2 and TM4 cells. We found autophagosome accumulation in GC-2 and TM4 cells after GOQDs treatment. Both LC3-II/LC3-I ratio and p62 levels increased, and the chloroquine-induced accumulation of LC3-II didn’t enhance in the presence of GOQDs, which indicated that GOQDs blocked autophagic flux. Further studies found that the fusion between autophagosome and lysosome was not inhibited by GOQDs, but the proteolytic capacity of lysosome was weakened and both the expression and activity of cathepsin B reduced. Taken together, these results suggested that GOQDs blocked autophagic flux by decreasing the amount and enzymatic activity of cathepsin B and inhibiting lysosome proteolytic capacity in GC-2 and TM4 cells, which might have a potential hazard to male reproduction.

  15. Upper GI Bleeding in Children

    Upper GI Bleeding in Children What is upper GI Bleeding? Irritation and ulcers of the lining of the esophagus, stomach or duodenum can result in upper GI bleeding. When this occurs the child may vomit blood ...

  16. Macrolide Antibiotics Exhibit Cytotoxic Effect under Amino Acid-Depleted Culture Condition by Blocking Autophagy Flux in Head and Neck Squamous Cell Carcinoma Cell Lines

    Hirasawa, Kazuhiro; Moriya, Shota; Miyahara, Kana; Kazama, Hiromi; Hirota, Ayako; Takemura, Jun; Abe, Akihisa; Inazu, Masato; Hiramoto, Masaki; Tsukahara, Kiyoaki

    2016-01-01

    Autophagy, a self-digestive system for cytoplasmic components, is required to maintain the amino acid pool for cellular homeostasis. We previously reported that the macrolide antibiotics azithromycin (AZM) and clarithromycin (CAM) have an inhibitory effect on autophagy flux, and they potently enhance the cytocidal effect of various anticancer reagents in vitro. This suggests that macrolide antibiotics can be used as an adjuvant for cancer chemotherapy. Since cancer cells require a larger metabolic demand than normal cells because of their exuberant growth, upregulated autophagy in tumor cells has now become the target for cancer therapy. In the present study, we examined whether macrolides exhibit cytotoxic effect under an amino acid-starving condition in head and neck squamous cancer cell lines such as CAL 27 and Detroit 562 as models of solid tumors with an upregulated autophagy in the central region owing to hypovascularity. AZM and CAM induced cell death under the amino acid-depleted (AAD) culture condition in these cell lines along with CHOP upregulation, although they showed no cytotoxicity under the complete culture medium. CHOP knockdown by siRNA in the CAL 27 cells significantly suppressed macrolide-induced cell death under the AAD culture condition. CHOP-/- murine embryonic fibroblast (MEF) cell lines also attenuated AZM-induced cell death compared with CHOP+/+ MEF cell lines. Using a tet-off atg5 MEF cell line, knockout of atg5, an essential gene for autophagy, also induced cell death and CHOP in the AAD culture medium but not in the complete culture medium. This suggest that macrolide-induced cell death via CHOP induction is dependent on autophagy inhibition. The cytotoxicity of macrolide with CHOP induction was completely cancelled by the addition of amino acids in the culture medium, indicating that the cytotoxicity is due to the insufficient amino acid pool. These data suggest the possibility of using macrolides for “tumor-starving therapy”. PMID

  17. Flux-line response in 2H-NbSe 2 investigated by means of the vibrating superconductor method

    D'Anna, G.; André, M.-O.; Benoit, W.; Rodríguez, E.; Rodríguez, D. S.; Luzuriaga, J.; Wasczak, J. V.

    1993-12-01

    We measure transverse AC losses in the low- and high-amplitude regime of 2H-NbSe 2 single crystals using vibrating superconductor methods. The measurements are sensitive to small deviations of the critical state. The data constitute evidence for a peak effect of the critical current as a function of the temperature in this compound. We construct in the H- T phase diagram the “peak-effect” line which is supposed to mark an abrupt cross-over in the vortex-pinning regime.

  18. Tetraethylammonium block of water flux in Aquaporin-1 channels expressed in kidney thin limbs of Henle's loop and a kidney-derived cell line.

    Pannabecker Thomas L

    2002-03-01

    Full Text Available Abstract Background Aquaporin-1 (AQP1 channels are constitutively active water channels that allow rapid transmembrane osmotic water flux, and also serve as cyclic-GMP-gated ion channels. Tetraethylammonium chloride (TEA; 0.05 to 10 mM was shown previously to inhibit the osmotic water permeability of human AQP1 channels expressed in Xenopus oocytes. The purpose of the present study was to determine if TEA blocks osmotic water flux of native AQP1 channels in kidney, and recombinant AQP1 channels expressed in a kidney derived MDCK cell line. We also demonstrate that TEA does not inhibit the cGMP-dependent ionic conductance of AQP1 expressed in oocytes, supporting the idea that water and ion fluxes involve pharmacologically distinct pathways in the AQP1 tetrameric complex. Results TEA blocked water permeability of AQP1 channels in kidney and kidney-derived cells, demonstrating this effect is not limited to the oocyte expression system. Equivalent inhibition is seen in MDCK cells with viral-mediated AQP1 expression, and in rat renal descending thin limbs of Henle's loops which abundantly express native AQP1, but not in ascending thin limbs which do not express AQP1. External TEA (10 mM does not block the cGMP-dependent AQP1 ionic conductance, measured by two-electrode voltage clamp after pre-incubation of oocytes in 8Br-cGMP (10–50 mM or during application of the nitric oxide donor, sodium nitroprusside (2–4 mM. Conclusions TEA selectively inhibits osmotic water permeability through native and heterologously expressed AQP1 channels. The pathways for water and ions in AQP1 differ in pharmacological sensitivity to TEA, and are consistent with the idea of independent solute pathways within the channel structure. The results confirm the usefulness of TEA as a pharmacological tool for the analysis of AQP1 function.

  19. Absolute on-line in-pile measurement of neutron fluxes using self-powered neutron detectors: Monte Carlo sensitivity calculations

    Vermeeren, L. [SCK/CEN, B-2400 Mol (Belgium)

    2001-07-01

    Self-powered neutron detectors (SPND) are well suited to monitor continuously the neutronic operating conditions of driver fuel of research reactors and to follow its burnup evolution. This is of particular importance when advanced or new MTR fuel designs need to be qualified. We have developed a detailed MCNP-4B based Monte Carlo approach for the calculation of neutron sensitivities of SPNDs. Results for the neutron sensitivity of a Rh SPND are in excellent agreement with experimental data recently obtained at the BR2 research reactor. A critical comparison of the Monte Carlo results with results from standard analytical methods reveals an important deficiency of the analytical methods in the description of the electron transport efficiency. Our calculation method allows a reliable on-line determination of the absolute in-pile neutron flux. (author)

  20. Structural stability of the square flux line lattice in YNi2B2C and LuNi2B2C studied with small angle neutron scattering

    Eskildsen, M.R.; Gammel, P.L.; Barber, B.P.

    1997-01-01

    We have studied the flux line lattice in YNi2B2C and LuNi2B2C, the nonmagnetic end members of the borocarbide superconductors using small angle neutron scattering and transport. For fields, H parallel to c, we find a square symmetric lattice which disorders rapidly above H/H-c2 similar to 0.2, well...... below the ''peak effect'' at H/H-c2 = 0.9. The results for H/H-c2 controlled by the tilt modulus c(44). For H/H-c2 > 0.2, the disordering appears to be associated with the field dependence of the shear modulus, C-66....

  1. Absolute on-line in-pile measurement of neutron fluxes using self-powered neutron detectors: Monte Carlo sensitivity calculations

    Vermeeren, L.

    2001-01-01

    Self-powered neutron detectors (SPND) are well suited to monitor continuously the neutronic operating conditions of driver fuel of research reactors and to follow its burnup evolution. This is of particular importance when advanced or new MTR fuel designs need to be qualified. We have developed a detailed MCNP-4B based Monte Carlo approach for the calculation of neutron sensitivities of SPNDs. Results for the neutron sensitivity of a Rh SPND are in excellent agreement with experimental data recently obtained at the BR2 research reactor. A critical comparison of the Monte Carlo results with results from standard analytical methods reveals an important deficiency of the analytical methods in the description of the electron transport efficiency. Our calculation method allows a reliable on-line determination of the absolute in-pile neutron flux. (author)

  2. A chicken influenza virus recognizes fucosylated α2,3 sialoglycan receptors on the epithelial cells lining upper respiratory tracts of chickens.

    Hiono, Takahiro; Okamatsu, Masatoshi; Nishihara, Shoko; Takase-Yoden, Sayaka; Sakoda, Yoshihiro; Kida, Hiroshi

    2014-05-01

    Influenza viruses recognize sialoglycans as receptors. Although viruses isolated form chickens preferentially bind to sialic acid α2,3 galactose (SAα2,3Gal) glycans as do those of ducks, chickens were not experimentally infected with viruses isolated from ducks. A chicken influenza virus, A/chicken/Ibaraki/1/2005 (H5N2) (Ck/IBR) bound to fucose-branched SAα2,3Gal glycans, whereas the binding towards linear SAα2,3Gal glycans was weak. On the epithelial cells of the upper respiratory tracts of chickens, fucose-branched SAα2,3Gal glycans were detected, but not linear SAα2,3Gal glycans. The growth of Ck/IBR in MDCK-FUT cells, which were genetically prepared to express fucose-branched SAα2,3Gal glycans, was significantly higher than that in the parental MDCK cells. The present results indicate that fucose-branched SAα2,3Gal glycans existing on the epithelial cells lining the upper respiratory tracts of chickens are critical for recognition by Ck/IBR. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Evaluation of an on-line methodology for measuring volatile organic compounds (VOC) fluxes by eddy-covariance with a PTR-TOF-Qi-MS

    Loubet, Benjamin; Buysse, Pauline; Lafouge, Florence; Ciuraru, Raluca; Decuq, Céline; Zurfluh, Olivier

    2017-04-01

    Field scale flux measurements of volatile organic compounds (VOC) are essential for improving our knowledge of VOC emissions from ecosystems. Many VOCs are emitted from and deposited to ecosystems. Especially less known, are crops which represent more than 50% of French terrestrial surfaces. In this study, we evaluate a new on-line methodology for measuring VOC fluxes by Eddy Covariance with a PTR-Qi-TOF-MS. Measurements were performed at the ICOS FR-GRI site over a crop using a 30 m long high flow rate sampling line and an ultrasonic anemometer. A Labview program was specially designed for acquisition and on-line covariance calculation: Whole mass spectra ( 240000 channels) were acquired on-line at 10 Hz and stored in a temporary memory. Every 5 minutes, the spectra were mass-calibrated and normalized by the primary ion peak integral at 10 Hz. The mass spectra peaks were then retrieved from the 5-min averaged spectra by withdrawing the baseline, determining the resolution and using a multiple-peak detection algorithm. In order to optimize the peak detection algorithm for the covariance, we determined the covariances as the integrals of the peaks of the vertical-air-velocity-fluctuation weighed-averaged-spectra. In other terms, we calculate , were w is the vertical component of the air velocity, Sp is the spectra, t is time, lag is the decorrelation lag time and denotes an average. The lag time was determined as the decorrelation time between w and the primary ion (at mass 21.022) which integrates the contribution of all reactions of VOC and water with the primary ion. Our algorithm was evaluated by comparing the exchange velocity of water vapor measured by an open path absorption spectroscopy instrument and the water cluster measured with the PTRQi-TOF-MS. The influence of the algorithm parameters and lag determination is discussed. This study was supported by the ADEME-CORTEA COV3ER project (http://www6.inra.fr/cov3er).

  4. Pathological evaluation of ganglion cells in biopsies from upper side of the dentate line in patients with perianal problems

    Marjan Joudi

    2014-07-01

    Full Text Available Introduction: Constipation is one of the most common complaints of individuals, which may present with complication like hemorrhoid and fissure. Hirschsprung is a disease presenting with chronic constipation and its diagnosis may be delayed until adulthood. It is diagnosed by biopsies from anorectal transitional zone. This study aimed to evaluate the association between Hirschsprung and anorectal problems. Method: Sixty three patients with anorectal problems who underwent surgery enrolled in this study. Some consecutive biopsies were obtained from anal canal at 2, 4 and 6 cm above the dentate line. Biopsies were assessed for ganglion cells changes. Patients' data and biopsies results were analyzed with SPSS version18. Results: Out of 63 patients 29 (46 % patients were female and 34 (54 % were male with the mean of 32.65 ± 13.73 years. Fifty six (73 % patients complained from constipation with the mean time of 57.65 ± 45.21 months. Aganglionic zone were reported in six patients with the mean length of 43.33 mm. There was not any relation between anal ganglion cells pathology and constipation (p=0.363, but there was a significant relation between duration of constipation and pathologic changes (p=0.001. The ratio of constipation duration to age was related to anal ganglion cell pathology (p=0.001. Hemorrhoid degree was also affected anal ganglion cells pathology (p=0.037. Conclusion: The relation between Hirschsprung's disease and anorectal problems in adults were significant. The pathologic findings were more presented in younger patients, and those with longer history of constipation and lower degree hemorrhoids. Key words: Anal ganglion cells, Hemorrhoids, Constipation  

  5. Upper limit to the deuterium abundance and a measurement of the pickering-β line in the low excitation planetary IC 418

    Le Vaux, H.A.

    1977-01-01

    The problem of detecting a weak spectrum line, deuterium alpha, very near in wavelength to H/sub alpha/, assumed to be thousands of times as strong, is discussed from the point of view of optimizing the signal-to-noise ratio. A spectrometer consisting of three pressure scanning Fabry-Perot etalons with low reflectivity coatings was found to be the best instrument for this experiment. While no feature attributable to deuterium was detected in the planetary nebula IC 418, an upper limit relative to hydrogen of 3.4 x 10 -5 was established at the 95% confidence level. The significance of this result is discussed in light of the role played by deuterium in cosmology. The intensity ratio of the Pickering beta line (n'' = 6, n' = 4 transition of ionized helium) relative to H/sub alpha/ was measured to be 6.5 x 10 -5 . Observations of the nebular continuum made at five wavelengths in the red and near infrared are summarized and compared with predicted intensities

  6. In line inspection of multi-diameter and high-pressure pipelines in Brazil using combined technologies: magnetic flux leakage and ultrasonic testing

    Ginten, Markus; Brockhaus, Stephan; Bouaoua, Nourreddine; Klein, Stefan [ROSEN Technology and Research Center, Lingen (Germany); Bruening, Franz [ROSEN Brazil, Rio de Janeiro, RJ (Brazil)

    2009-07-01

    The simultaneous use of the magnetic flux leakage (MFL) method and the ultrasonic testing (UT) method on a single in line inspection (ILI) tool has been identified as a versatile and accurate solution for liquid pipelines. The combination of the two methods is complementary to the restrictions of each other. Also, the overall scope of the inspection is enlarged. General wall thinning and largely corroded areas are accurately and reliably scanned with the UT unit, while very detailed information about pitting corrosion is obtained from the MFL measurement. Blind spots of echo loss, as occasionally observed for the UT channels is compensated by the more robust measurement from the MFL sensors. Consequently, this technology has been the method of choice in an in line inspection project of an onshore long distance pipeline in Brazil, facing a variety of corrosion threats. The pipeline consists of several multi-diameter sections of 18/20 inches and 20/22 inches. Furthermore, the high gravity of product in combination with a height profile, an altitude of 1152 m MSL (Mean Sea Level) had to be crossed, leads to a maximum pressure of 220 bar. These boundary conditions had to be considered during the design of the ILI-tool. The paper discusses the experience made so far with the combined technology MFL and UT. The effective use of the inspection tool for the above mentioned pipeline as well as field results from a previous inspection are described. (author)

  7. Variations of daytime and nighttime electron temperature and heat flux in the upper ionosphere, topside ionosphere and lower plasmasphere for low and high solar activity

    Truhlík, Vladimír; Třísková, Ludmila; Bilitza, D.; Podolská, Kateřina

    2009-01-01

    Roč. 71, 17-18 (2009), s. 2055-2063 ISSN 1364-6826 R&D Projects: GA AV ČR IAA300420603 Grant - others: NASA (US) NNH06CD17C Institutional research plan: CEZ:AV0Z30420517 Keywords : Electron temperature * Solar activity variation * Latitudinal and field aligned profiles * Heat flux Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 1.643, year: 2009

  8. Secondary cosmic-ray e+- from 1 to 100 GeV in the upper atmosphere and interstellar space, and interpretation of a recent e+ flux measurement

    Orth, C.D.; Buffington, A.

    1976-01-01

    Secondary fluxes of cosmic-ray e from the decay of mesons produced by nuclear interactions are calculated for depths under 10 g cm -2 of atmosphere or interstellar space for energies from 1 to 100 GeV. Secondary meson spectra applicable for energies > or =5 GeV are obtained from the recently measured spectra of Carey et al. using Monte Carlo techniques. An analytic model is presented which identifies all essential parameters and enables easy calculation of efluxes for various parameter values. This model is used to interpret the e + measurement of Buffington, Orth, and Smoot. We find the mean thickness of interstellar and source material to be 4.3 (+1.8,-1.2) g cm -2 for cosmic-ray e + above 4 GeV. This result is difficult to reconcile with the recently proposed two-containment-volume propagation models of Cowsik and Wilson; Rengarajan, Stephens, and Verma; and Meneguzzi: all of the models predict a result near 1.8 g cm -2 at these energies due to the energy dependence of the measured (Li+Be+B)/(C+O) ratio. Single-containment-volume (galactic) models invoking an energy-dependent leakage lifetime are compatible with the e + data, but lack a mechanism to explain the energy dependence

  9. Upper respiratory tract (image)

    The major passages and structures of the upper respiratory tract include the nose or nostrils, nasal cavity, mouth, throat (pharynx), and voice box (larynx). The respiratory system is lined with a mucous membrane that ...

  10. Comparison of survival between dialysis patients with incident high-flux hemodialysis versus on-line hemodiafiltration: A single center experience in Saudi Arabia

    Mohamed Said Abdelsalam

    2018-01-01

    Full Text Available Conventional hemodialysis (HD is the most common treatment modality used for renal replacement therapy. The concept of HD is based on the diffusion of solutes across a semipermeable membrane. Hemofiltration (HF is based on convective transport of solutes; hemodiafiltration (HDF is based on combined convective and diffusive therapies. Data about survival benefit of on-line HDF (OL-HDF over high-flux HD (HF-HD is conflicting. We conducted this study to investigate if there is a survival difference between the two treatment modalities. This study is a retrospective, single-center study in which 78 patients were screened; 18 were excluded and 60 patients were analyzed. The study patients were aged 47.5 ± 20.7 years, 33 patients (55% were on HF-HD, and 27 patients (45% were on OL-HDF. A total of 24 patients (40% of both groups were diabetic and, the mean duration on dialysis was 43.5 ±21.3 months in the HF-HD group and 41.2 ± 22.0 months in the OL-HDF group. The mean substitution volume for OL-HDF was 22.3 ± 2.5 L. Survival was 73% [95%, confidence interval (CI 60–84] in the HF-HD group and 65% (95%, CI 54–75 in the OL-HDF group by the end of the study period. The unadjusted hazard ratio (HR with 95% CI comparing HF-HD to high-volume postdilution OL-HDF was 0.78 (0.10–5.6; P = 0.810. Kaplan–Meier analysis for patient survival over five years showed no significant difference between the two modalities. Prospective controlled trials with a larger number of patients will be needed to assess the long-term clinical outcome of postdilution OL-HDF over HF-HD.

  11. TIGER/Line Shapefile, 2014, Series Information File for the Current State Legislative District (SLD) Upper Chamber State-based Shapefile

    US Census Bureau, Department of Commerce — State Legislative Districts (SLDs) are the areas from which members are elected to State legislatures. The SLDs embody the upper (senate) and lower (house) chambers...

  12. Flux cutting in superconductors

    Campbell, A M

    2011-01-01

    This paper describes experiments and theories of flux cutting in superconductors. The use of the flux line picture in free space is discussed. In superconductors cutting can either be by means of flux at an angle to other layers of flux, as in longitudinal current experiments, or due to shearing of the vortex lattice as in grain boundaries in YBCO. Experiments on longitudinal currents can be interpreted in terms of flux rings penetrating axial lines. More physical models of flux cutting are discussed but all predict much larger flux cutting forces than are observed. Also, cutting is occurring at angles between vortices of about one millidegree which is hard to explain. The double critical state model and its developments are discussed in relation to experiments on crossed and rotating fields. A new experiment suggested by Clem gives more direct information. It shows that an elliptical yield surface of the critical state works well, but none of the theoretical proposals for determining the direction of E are universally applicable. It appears that, as soon as any flux flow takes place, cutting also occurs. The conclusion is that new theories are required. (perspective)

  13. Development and Implementation of an End-Effector Upper Limb Rehabilitation Robot for Hemiplegic Patients with Line and Circle Tracking Training

    Yali Liu

    2017-01-01

    Full Text Available Numerous robots have been widely used to deliver rehabilitative training for hemiplegic patients to improve their functional ability. Because of the complexity and diversity of upper limb motion, customization of training patterns is one key factor during upper limb rehabilitation training. Most of the current rehabilitation robots cannot intelligently provide adaptive training parameters, and they have not been widely used in clinical rehabilitation. This article proposes a new end-effector upper limb rehabilitation robot, which is a two-link robotic arm with two active degrees of freedom. This work investigated the kinematics and dynamics of the robot system, the control system, and the realization of different rehabilitation therapies. We also explored the influence of constraint in rehabilitation therapies on interaction force and muscle activation. The deviation of the trajectory of the end effector and the required trajectory was less than 1 mm during the tasks, which demonstrated the movement accuracy of the robot. Besides, results also demonstrated the constraint exerted by the robot provided benefits for hemiplegic patients by changing muscle activation in the way similar to the movement pattern of the healthy subjects, which indicated that the robot can improve the patient’s functional ability by training the normal movement pattern.

  14. A semi-experimental nodal synthesis method for the on-line reconstruction of three-dimensional neutron flux-shapes and reactivity

    Jacqmin, R.P.

    1991-01-01

    The safety and optimal performance of large, commercial, light-water reactors require the knowledge at all time of the neutron-flux distribution in the core. In principle, this information can be obtained by solving the time-dependent neutron diffusion equations. However, this approach is complicated and very expensive. Sufficiently accurate, real-time calculations (time scale of approximately one second) are not yet possible on desktop computers, even with fast-running, nodal kinetics codes. A semi-experimental, nodal synthesis method which avoids the solution of the time-dependent, neutron diffusion equations is described. The essential idea of this method is to approximate instantaneous nodal group-fluxes by a linear combination of K, precomputed, three-dimensional, static expansion-functions. The time-dependent coefficients of the combination are found from the requirement that the reconstructed flux-distribution agree in a least-squares sense with the readings of J (≥K) fixed, prompt-responding neutron-detectors. Possible numerical difficulties with the least-squares solution of the ill-conditioned, J-by-K system of equations are brought under complete control by the use of a singular-value-decomposition technique. This procedure amounts to the rearrangement of the original, linear combination of K expansion functions into an equivalent more convenient, linear combination of R (≤K) orthogonalized ''modes'' of decreasing magnitude. Exceedingly small modes are zeroed to eliminate any risk of roundoff-error amplification, and to assure consistency with the limited accuracy of the data. Additional modes are zeroed when it is desirable to limit the sensitivity of the results to measurement noise

  15. A semi-experimental nodal synthesis method for the on-line reconstruction of three-dimensional neutron flux-shapes and reactivity. Final report

    Jacqmin, Robert P. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    1991-12-10

    The safety and optimal performance of large, commercial, light-water reactors require the knowledge at all time of the neutron-flux distribution in the core. In principle, this information can be obtained by solving the time-dependent neutron diffusion equations. However, this approach is complicated and very expensive. Sufficiently accurate, real-time calculations (time scale of approximately one second) are not yet possible on desktop computers, even with fast-running, nodal kinetics codes. A semi-experimental, nodal synthesis method which avoids the solution of the time-dependent, neutron diffusion equations is described. The essential idea of this method is to approximate instantaneous nodal group-fluxes by a linear combination of K, precomputed, three-dimensional, static expansion-functions. The time-dependent coefficients of the combination are found from the requirement that the reconstructed flux-distribution agree in a least-squares sense with the readings of J (≥K) fixed, prompt-responding neutron-detectors. Possible numerical difficulties with the least-squares solution of the ill-conditioned, J-by-K system of equations are brought under complete control by the use of a singular-value-decomposition technique. This procedure amounts to the rearrangement of the original, linear combination of K expansion functions into an equivalent more convenient, linear combination of R (≤K) orthogonalized ``modes`` of decreasing magnitude. Exceedingly small modes are zeroed to eliminate any risk of roundoff-error amplification, and to assure consistency with the limited accuracy of the data. Additional modes are zeroed when it is desirable to limit the sensitivity of the results to measurement noise.

  16. A semi-experimental nodal synthesis method for the on-line reconstruction of three-dimensional neutron flux-shapes and reactivity

    Jacqmin, R.P.

    1991-12-10

    The safety and optimal performance of large, commercial, light-water reactors require the knowledge at all time of the neutron-flux distribution in the core. In principle, this information can be obtained by solving the time-dependent neutron diffusion equations. However, this approach is complicated and very expensive. Sufficiently accurate, real-time calculations (time scale of approximately one second) are not yet possible on desktop computers, even with fast-running, nodal kinetics codes. A semi-experimental, nodal synthesis method which avoids the solution of the time-dependent, neutron diffusion equations is described. The essential idea of this method is to approximate instantaneous nodal group-fluxes by a linear combination of K, precomputed, three-dimensional, static expansion-functions. The time-dependent coefficients of the combination are found from the requirement that the reconstructed flux-distribution agree in a least-squares sense with the readings of J ({ge}K) fixed, prompt-responding neutron-detectors. Possible numerical difficulties with the least-squares solution of the ill-conditioned, J-by-K system of equations are brought under complete control by the use of a singular-value-decomposition technique. This procedure amounts to the rearrangement of the original, linear combination of K expansion functions into an equivalent more convenient, linear combination of R ({le}K) orthogonalized modes'' of decreasing magnitude. Exceedingly small modes are zeroed to eliminate any risk of roundoff-error amplification, and to assure consistency with the limited accuracy of the data. Additional modes are zeroed when it is desirable to limit the sensitivity of the results to measurement noise.

  17. Force sensor using changes in magnetic flux

    Pickens, Herman L. (Inventor); Richard, James A. (Inventor)

    2012-01-01

    A force sensor includes a magnetostrictive material and a magnetic field generator positioned in proximity thereto. A magnetic field is induced in and surrounding the magnetostrictive material such that lines of magnetic flux pass through the magnetostrictive material. A sensor positioned in the vicinity of the magnetostrictive material measures changes in one of flux angle and flux density when the magnetostrictive material experiences an applied force that is aligned with the lines of magnetic flux.

  18. Upper Triassic mafic dykes of Lake Nyos, Cameroon (West Africa) I: K-Ar age evidence within the context of Cameroon Line magmatism, and the tectonic significance

    Aka, Festus Tongwa; Hasegawa, Takeshi; Nche, Linus Anye; Asaah, Asobo Nkengmatia Elvis; Mimba, Mumbfu Ernestine; Teitchou, Isidore; Ngwa, Caroline; Miyabuchi, Yasuo; Kobayashi, Tetsuo; Kankeu, Boniface; Yokoyama, Tetsuya; Tanyileke, Gregory; Ohba, Takeshi; Hell, Joseph Victor; Kusakabe, Minoru

    2018-05-01

    The hydrodynamic fragmentation that formed Lake Nyos in northwest Cameroon did not only make it the most unpopular lake in the world from a gas disaster perspective, it also opened a rare and formidable window through which much of the geology of Cameroon can be studied in a single locality. The Cambrian quartz monzonite cliff excavated by the maar-forming explosion and exposed in its northeastern shore is intruded by mafic dykes, two of which we dated. Even though close to one another, the dykes are different in composition. The alkaline dyke yields a slightly older (Carnian) K-Ar fedspar age of 231.1 ± 4.8 Ma, while the sub alkaline dyke yields an age of 224.8 ± 4.7 Ma (Norian). Based on radioisotopic age data available over the last 48 years (347 data) for the Cameroon Line magmatism comprising eruptives and volcano-plutonic complexes, the Nyos dykes are way older than the Cameroon Line, and even pre-date the Lower Cretaceous initiation of west Gondwana fragmentation in Equatorial Atlantic domain. They would therefore not have been directly linked to the formation of the Cameroon Line. Alternatively, they might be associated with the development of intra-continental rift systems in West Central Africa that pre-dated west Gondwana breakup to form the Atlantic Ocean.

  19. Dark matter line emission constraints from NuSTAR observations of the Bullet Cluster

    Riemer-Sørensen, S.; Wik, D.; Madejski, G.

    2015-01-01

    Some dark matter candidates, e.g., sterile neutrinos, provide observable signatures in the form of mono-energetic line emission. We present the first search for dark matter line emission in the range in a pointed observation of the Bullet Cluster with NuSTAR. We do not detect any significant line...... emission and instead we derive upper limits (95% CL) on the flux, and interpret these constraints in the context of sterile neutrinos and more generic dark matter candidates. NuSTAR does not have the sensitivity to constrain the recently claimed line detection at , but improves on the constraints...... for energies of 10–25 keV....

  20. Gemini long-slit observations of luminous obscured quasars: Further evidence for an upper limit on the size of the narrow-line region

    Hainline, Kevin N.; Hickox, Ryan C.; Greene, Jenny E.; Myers, Adam D.; Zakamska, Nadia L.; Liu, Guilin; Liu, Xin

    2014-01-01

    We examine the spatial extent of the narrow-line regions (NLRs) of a sample of 30 luminous obscured quasars at 0.4 < z < 0.7 observed with spatially resolved Gemini-N GMOS long-slit spectroscopy. Using the [O III] λ5007 emission feature, we estimate the size of the NLR using a cosmology-independent measurement: the radius where the surface brightness falls to 10 –15 erg s –1 cm –2 arcsec –2 . We then explore the effects of atmospheric seeing on NLR size measurements and conclude that direct measurements of the NLR size from observed profiles are too large by 0.1-0.2 dex on average, as compared to measurements made to best-fit Sérsic or Voigt profiles convolved with the seeing. These data, which span a full order of magnitude in IR luminosity (log (L 8 μm /erg s –1 ) = 44.4-45.4), also provide strong evidence that there is a flattening of the relationship between NLR size and active galactic nucleus luminosity at a seeing-corrected size of ∼7 kpc. The objects in this sample have high luminosities which place them in a previously under-explored portion of the size-luminosity relationship. These results support the existence of a maximal size of the NLR around luminous quasars; beyond this size, there is either not enough gas or the gas is over-ionized and does not produce enough [O III] λ5007 emission.

  1. MEASURING THE SOURCES OF THE INTERGALACTIC IONIZING FLUX

    Cowie, L. L.; Barger, A. J.; Trouille, L.

    2009-01-01

    We use a wide-field (0.9 deg 2 ) X-ray sample with optical and Galaxy Evolution Explorer (GALEX) ultraviolet observations to measure the contribution of active galactic nuclei (AGNs) to the ionizing flux as a function of redshift. Our analysis shows that the AGN contribution to the metagalactic ionizing background peaks at around z = 2. The measured values of the ionizing background from the AGNs are lower than previous estimates and confirm that ionization from AGNs is insufficient to maintain the observed ionization of the intergalactic medium (IGM) at z > 3. We show that only X-ray sources with broad lines in their optical spectra have detectable ionizing flux and that the ionizing flux seen in an AGN is not correlated with its X-ray color. We also use the GALEX observations of the GOODS-N region to place a 2σ upper limit of 0.008 on the average ionization fraction f ν (700 A)/f ν (1500 A) for 626 UV selected galaxies in the redshift range z = 0.9-1.4. We then use this limit to estimate an upper bound to the galaxy contribution in the redshift range z = 0-5. If the z ∼ 1.15 ionization fraction is appropriate for higher-redshift galaxies, then contributions from the galaxy population are also too low to account for the IGM ionization at the highest redshifts (z > 4).

  2. PROJECT-SPECIFIC TYPE A VERIFICATION FOR THE HIGH FLUX BEAM REACTOR UNDERGROUND UTILITIES REMOVAL PHASE 2 D/F WASTE LINE REMOVAL, BROOKHAVEN NATIONAL LABORATORY UPTON, NEW YORK

    Weaver, P.C.

    2010-01-01

    Oak Ridge Institute for Science and Education (ORISE) has reviewed the project documentation and data for the High Flux Beam Reactor (HFBR) Underground Utilities removal Phase 2; the D/F Waste Line removal at Brookhaven National Laboratory (BNL) in Upton, New York. The Brookhaven Survey Group (BSG) has completed removal and performed the final status survey (FSS) of the D/F Waste Line that provided the conduit for pumping waste from Building 750 to Building 801. Sample results have been submitted as required to demonstrate that the cleanup goals of 15 mrem/yr above background to a resident in 50 years have been met. Four rounds of sampling, from pre-excavation to final status survey (FSS), were performed as specified in the Field Sampling Plan (FSP) (BNL 2010a). It is the policy of the US Departmental of Energy (DOE) to perform independent verifications of decontamination and decomissioning activities conducted at DOE facilities. ORISE has been designated as the organization responsible for this task at the HFBR. ORISE together with DOE determined that a Type A verification of the D/F Waste Line was appropriate based on its method of construction and upon the minimal potential for residual radioactivity in the area. The removal of underground utilities is being performed in three stages in the process to decommission the HFBR facility and support structures. Phase 2 of this project included the grouting and removal of 1100 feet of 2-inch pipe and 640 feet of 4-inch pipe that served as the D/F Waste Line. Based on the pre-excavation sample results of the soil overburden, the potential for contamination of the soil surrounding the pipe is minimal (BNL 2010a). ORISE reviewed the BNL FSP and identified comments for consideration (ORISE 2010). BNL prepared a revised FSP that addressed each ORISE comment adequately (BNL 2010a). ORISE referred to the revised Phase 2 D/F Waste Line removal FSP FSS data to conduct the Type A verification and determine whether the intent odf

  3. Topology of magnetic flux ropes and formation of fossil flux transfer events and boundary layer plasmas

    Lee, L. C.; Ma, Z. W.; Fu, Z. F.; Otto, A.

    1993-01-01

    A mechanism for the formation of fossil flux transfer events and the low-level boundary layer within the framework of multiple X-line reconnection is proposed. Attention is given to conditions for which the bulk of magnetic flux in a flux rope of finite extent has a simple magnetic topology, where the four possible connections of magnetic field lines are: IMF to MSP, MSP to IMF, IMF to IMF, and MSP to MSP. For a sufficient relative shift of the X lines, magnetic flux may enter a flux rope from the magnetosphere and exit into the magnetosphere. This process leads to the formation of magnetic flux ropes which contain a considerable amount of magnetosheath plasma on closed magnetospheric field lines. This process is discussed as a possible explanation for the formation of fossil flux transfer events in the magnetosphere and the formation of the low-latitude boundary layer.

  4. Properties of Narrow line Seyfert 1 galaxies

    Rakshit, Suvendu; Stalin, Chelliah Subramonian; Chand, Hum; Zhang, Xue-Guang

    2018-04-01

    Narrow line Seyfert 1 (NLSy1) galaxies constitute a class of active galactic nuclei characterized by the full width at half maximum (FWHM) of the Hα broad emission line 10 pixel-1. A strong correlation between the Hα and Hα emission lines is found both in the FWHM and flux. The nuclear continuum luminosity is found to be strongly correlated with the luminosity of Hα, Hα and [O III] emission lines. The black hole mass in NLSy1 galaxies is lower compared to their broad line counterparts. Compared to BLSy1 galaxies, NLSy1 galaxies have a stronger FeII emission and a higher Eddington ratio that place them in the extreme upper right corner of the R4570 - λEdd diagram. The distribution of the radio-loudness parameter (R) in NLSy1 galaxies drops rapidly at R>10 compared to the BLSy1 galaxies that have powerful radio jets. The soft X-ray photon index in NLSy1 galaxies is on average higher (2.9 ± 0.9) than BLSy1 galaxies (2.4 ± 0.8). It is anti-correlated with the Hα width but correlated with the FeII strength. NLSy1 galaxies on average have a lower amplitude of optical variability compared to their broad lines counterparts. These results suggest Eddington ratio as the main parameter that drives optical variability in these sources.

  5. Observation of atomic oxygen O(1S) green-line emission in the summer polar upper mesosphere associated with high-energy (≥30 keV) electron precipitation during high-speed solar wind streams

    Lee, Young-Sook; Kwak, Young-Sil; Kim, Kyung-Chan; Solheim, Brian; Lee, Regina; Lee, Jaejin

    2017-01-01

    The auroral green-line emission at 557.7 nm wavelength as arising from the atomic oxygen O(1S → 1D) transition typically peaks at an altitude of 100 km specifically in the nightside oval, induced by auroral electrons within an energy range of 100 eV-30 keV. Intense aurora is known as being suppressed by sunlight in summer daytime but usually occurs in low electrical background conductivity. However, in the present study in summer (July) sunlit condition, enhancements of O(1S) emission rates observed by using the Wind Imaging Interferometer/UARS were frequently observed at low altitudes below 90 km, where ice particles are created initially as subvisible and detected as polar mesosphere summer echoes, emerging to be an optical phenomenon of polar mesospheric clouds. The intense O(1S) emission occurring in summer exceeds those occurring in the daytime in other seasons both in occurrence and in intensity, frequently accompanied by occurrences of supersonic neutral velocity (300-1500 m s-1). In the mesosphere, ion motion is controlled by electric field and the momentum is transferred to neutrals. The intense O(1S) emission is well associated with high-energy electron precipitation as observed during an event of high-speed solar wind streams. Meanwhile, since the minimum occurrences of O(1S) emission and supersonic velocity are maintained even in the low precipitation flux, the mechanism responsible is not only related to high-energy electron precipitation but also presumably to the local conditions, including the composition of meteoric-charged ice particles and charge separation expected in extremely low temperatures (<150 K).

  6. Directed line liquids

    Kamien, R.D.

    1992-01-01

    This thesis is devoted to the study of ensembles of dense directed lines. These lines are principally to be thought of as polymers, though they also have the morphology of flux lines in high temperature superconductors, strings of colloidal spheres in electrorheological fluids and the world lines of quantum mechanical bosons. The authors discuss how directed polymer melts, string-like formations in electrorheological and ferro-fluids, flux lines in high temperature superconductors and the world lines of quantum mechanical bosons all share similar descriptions. They study a continuous transition in all of these systems, and then study the critical mixing properties of binary mixtures of directed polymers through the renormalization group. They predict the exponents for a directed polymer blend consolute point and a novel two-phase superfluid liquid-gas critical point

  7. Ideal flux field dielectric concentrators.

    García-Botella, Angel

    2011-10-01

    The concept of the vector flux field was first introduced as a photometrical theory and later developed in the field of nonimaging optics; it has provided new perspectives in the design of concentrators, overcoming standard ray tracing techniques. The flux field method has shown that reflective concentrators with the geometry of the field lines achieve the theoretical limit of concentration. In this paper we study the role of surfaces orthogonal to the field vector J. For rotationally symmetric systems J is orthogonal to its curl, and then a family of surfaces orthogonal to the lines of J exists, which can be called the family of surfaces of constant pseudopotential. Using the concept of the flux tube, it is possible to demonstrate that refractive concentrators with the shape of these pseudopotential surfaces achieve the theoretical limit of concentration.

  8. Critical flux determination by flux-stepping

    Beier, Søren; Jonsson, Gunnar Eigil

    2010-01-01

    In membrane filtration related scientific literature, often step-by-step determined critical fluxes are reported. Using a dynamic microfiltration device, it is shown that critical fluxes determined from two different flux-stepping methods are dependent upon operational parameters such as step...... length, step height, and.flux start level. Filtrating 8 kg/m(3) yeast cell suspensions by a vibrating 0.45 x 10(-6) m pore size microfiltration hollow fiber module, critical fluxes from 5.6 x 10(-6) to 1.2 x 10(-5) m/s have been measured using various step lengths from 300 to 1200 seconds. Thus......, such values are more or less useless in itself as critical flux predictors, and constant flux verification experiments have to be conducted to check if the determined critical fluxes call predict sustainable flux regimes. However, it is shown that using the step-by-step predicted critical fluxes as start...

  9. Fermi LAT Search for Dark Matter in Gamma-Ray Lines and the Inclusive Photon Spectrum

    Ackermann, M.; Ajello, M.; Albert, A.; Baldini, L.; Barbiellini, G.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; hide

    2012-01-01

    Dark matter particle annihilation or decay can produce monochromatic gamma-ray lines and contribute to the diffuse gamma-ray background. Flux upper limits are presented for gamma-ray spectral lines from 7 to 200 GeV and for the diffuse gamma-ray background from 4.8 GeV to 264 GeV obtained from two years of Fermi Large Area Telescope data integrated over most of the sky. We give cross section upper limits and decay lifetime lower limits for dark matter models that produce gamma-ray lines or contribute to the diffuse spectrum, including models proposed as explanations of the PAMELA and Fermi cosmic-ray data.

  10. PREDICTING Lyα AND Mg II FLUXES FROM K AND M DWARFS USING GALAXY EVOLUTION EXPLORER ULTRAVIOLET PHOTOMETRY

    Shkolnik, Evgenya L.; Rolph, Kristina A.; Peacock, Sarah; Barman, Travis S.

    2014-01-01

    A star's ultraviolet (UV) emission can greatly affect the atmospheric chemistry and physical properties of closely orbiting planets with the potential for severe mass loss. In particular, the Lyα emission line at 1216 Å, which dominates the far-ultraviolet (FUV) spectrum, is a major source of photodissociation of important atmospheric molecules such as water and methane. The intrinsic flux of Lyα, however, cannot be directly measured due to the absorption of neutral hydrogen in the interstellar medium and contamination by geocoronal emission. To date, reconstruction of the intrinsic Lyα line based on Hubble Space Telescope spectra has been accomplished for 46 FGKM nearby stars, 28 of which have also been observed by the Galaxy Evolution Explorer (GALEX). Our investigation provides a correlation between published intrinsic Lyα and GALEX far- and near-ultraviolet (NUV) chromospheric fluxes for K and M stars. The negative correlations between the ratio of the Lyα to the GALEX fluxes reveal how the relative strength of Lyα compared to the broadband fluxes weakens as the FUV and NUV excess flux increase. We also correlate GALEX fluxes with the strong NUV Mg II h+k spectral emission lines formed at lower chromospheric temperatures than Lyα. The reported correlations provide estimates of intrinsic Lyα and Mg II fluxes for the thousands of K and M stars in the archived GALEX all-sky surveys. These will constrain new stellar upper atmosphere models for cool stars and provide realistic inputs to models describing exoplanetary photochemistry and atmospheric evolution in the absence of UV spectroscopy

  11. A tangent subsolar merging line

    Crooker, N.U.; Siscoe, G.L.; Toffoletto, F.R.

    1990-01-01

    The authors describe a global magnetospheric model with a single subsolar merging line whose position is determined neither locally by the relative orientations and strengths of the merging fields nor globally by the orientation of a separator line--the governing parameters of most previous models--but by the condition of tangential contact between the external field and the magnetopause. As in previous models, the tilt of the merging line varies with IMF orientation, but here it also depends upon the ratio of Earth's magnetic flux that leaks out of the magnetopause to IMF flux that penetrates in. In the limiting case treated by Alekseyev and Belen'kaya, with no leakage of Earth's field and total IMF penetration, the merging line forms a great circle around a spherical magnetosphere where undeviated IMF lines lie tangent to its surface. This tangent merging line lies perpendicular to the IMF. They extend their work to the case of finite leakage and partial penetration, which distort the IMF into a draped pattern, thus changing the locus of tangency to the sphere. In the special case where the penetrating IMF flux is balanced by an equal amount of Earth flux leakage, the tangent merging line bisects the angle between the IMF and Earth's northward subsolar field. This result is identical to the local merging line model result for merging fields with equal magnitude. Here a global flux balance condition replaces the local equal magnitude condition

  12. FSFE: Fake Spectra Flux Extractor

    Bird, Simeon

    2017-10-01

    The fake spectra flux extractor generates simulated quasar absorption spectra from a particle or adaptive mesh-based hydrodynamic simulation. It is implemented as a python module. It can produce both hydrogen and metal line spectra, if the simulation includes metals. The cloudy table for metal ionization fractions is included. Unlike earlier spectral generation codes, it produces absorption from each particle close to the sight-line individually, rather than first producing an average density in each spectral pixel, thus substantially preserving more of the small-scale velocity structure of the gas. The code supports both Gadget (ascl:0003.001) and AREPO.

  13. Magnetic-flux pump

    Hildebrandt, A. F.; Elleman, D. D.; Whitmore, F. C. (Inventor)

    1966-01-01

    A magnetic flux pump is described for increasing the intensity of a magnetic field by transferring flux from one location to the magnetic field. The device includes a pair of communicating cavities formed in a block of superconducting material, and a piston for displacing the trapped magnetic flux into the secondary cavity producing a field having an intense flux density.

  14. Radon flux measurement methodologies

    Nielson, K.K.; Rogers, V.C.

    1984-01-01

    Five methods for measuring radon fluxes are evaluated: the accumulator can, a small charcoal sampler, a large-area charcoal sampler, the ''Big Louie'' charcoal sampler, and the charcoal tent sampler. An experimental comparison of the five flux measurement techniques was also conducted. Excellent agreement was obtained between the measured radon fluxes and fluxes predicted from radium and emanation measurements

  15. IUE and Einstein survey of late-type giant and supergiant stars and the dividing line

    Haisch, Bernhard M.; Bookbinder, Jay A.; Maggio, A.; Vaiana, G. S.; Bennett, Jeffrey O.

    1990-01-01

    Results are presented on an IUE UV survey of 255 late-type G, K, and M stars, complementing the Maggio et al. (1990) Einstein X-ray survey of 380 late-type stars. The large data sample of X-ray and UV detections make it possible to examine the activity relationship between the X-ray and the UV emissions. The results confirm previous finding of a trend involving a steeply-dropping upper envelope of the transition region line fluxes, f(line)/f(V), as the dividing line is approached. This suggests that a sharp decrease in maximum activity accompanies the advancing spectral type, with the dividing line corresponding to this steep gradient region. The results confirm the rotation-activity connection for stars in this region of the H-R diagram.

  16. Flux flow and flux dynamics in high-Tc superconductors

    Bennett, L.H.; Turchinskaya, M.; Swartzendruber, L.J.; Roitburd, A.; Lundy, D.; Ritter, J.; Kaiser, D.L.

    1991-01-01

    Because high temperature superconductors, including BYCO and BSSCO, are type 2 superconductors with relatively low H(sub c 1) values and high H(sub c 2) values, they will be in a critical state for many of their applications. In the critical state, with the applied field between H(sub c 1) and H(sub c 2), flux lines have penetrated the material and can form a flux lattice and can be pinned by structural defects, chemical inhomogeneities, and impurities. A detailed knowledge of how flux penetrates the material and its behavior under the influence of applied fields and current flow, and the effect of material processing on these properties, is required in order to apply, and to improve the properties of these superconductors. When the applied field is changed rapidly, the time dependence of flux change can be divided into three regions, an initial region which occurs very rapidly, a second region in which the magnetization has a 1n(t) behavior, and a saturation region at very long times. A critical field is defined for depinning, H(sub c,p) as that field at which the hysteresis loop changes from irreversible to reversible. As a function of temperature, it is found that H(sub c,p) is well described by a power law with an exponent between 1.5 and 2.5. The behavior of H(sub c,p) for various materials and its relationship to flux flow and flux dynamics are discussed

  17. Oncoplastic Surgery for Upper/Upper Inner Quadrant Breast Cancer.

    Lin, Joseph; Chen, Dar-Ren; Wang, Yu-Fen; Lai, Hung-Wen

    2016-01-01

    Tumors located in the upper/upper inner quadrant of the breast warrant more attention. A small lesion relative to the size of breast in this location may be resolved by performing a level I oncoplastic technique. However, a wide excision may significantly reduce the overall quality of the breast shape by distorting the visible breast line. From June 2012 to April 2015, 36 patients with breast cancer located in the upper/upper inner quadrant underwent breast-conservation surgery with matrix rotation mammoplasty. According to the size and location of the tumor relative to the nipple-areola complex, 11 patients underwent matrix rotation with periareolar de-epithelialization (donut group) and the other 25 underwent matrix rotation only (non-donut group). The cosmetic results were self-assessed by questionnaires. The average weights of the excised breast lumps in the donut and non-donut groups were 104.1 and 84.5 g, respectively. During the 3-year follow-up period, local recurrence was observed in one case and was managed with nipple-sparing mastectomy followed by breast reconstruction with prosthetic implants. In total, 31 patients (88.6%) ranked their postoperative result as either acceptable or satisfactory. The treated breasts were also self-evaluated by 27 patients (77.1%) to be nearly identical to or just slightly different from the untreated side. Matrix rotation is an easy breast-preserving technique for treating breast cancer located in the upper/upper inner quadrant of the breast that requires a relatively wide excision. With this technique, a larger breast tumor could be removed without compromising the breast appearance.

  18. Oncoplastic Surgery for Upper/Upper Inner Quadrant Breast Cancer.

    Joseph Lin

    Full Text Available Tumors located in the upper/upper inner quadrant of the breast warrant more attention. A small lesion relative to the size of breast in this location may be resolved by performing a level I oncoplastic technique. However, a wide excision may significantly reduce the overall quality of the breast shape by distorting the visible breast line. From June 2012 to April 2015, 36 patients with breast cancer located in the upper/upper inner quadrant underwent breast-conservation surgery with matrix rotation mammoplasty. According to the size and location of the tumor relative to the nipple-areola complex, 11 patients underwent matrix rotation with periareolar de-epithelialization (donut group and the other 25 underwent matrix rotation only (non-donut group. The cosmetic results were self-assessed by questionnaires. The average weights of the excised breast lumps in the donut and non-donut groups were 104.1 and 84.5 g, respectively. During the 3-year follow-up period, local recurrence was observed in one case and was managed with nipple-sparing mastectomy followed by breast reconstruction with prosthetic implants. In total, 31 patients (88.6% ranked their postoperative result as either acceptable or satisfactory. The treated breasts were also self-evaluated by 27 patients (77.1% to be nearly identical to or just slightly different from the untreated side. Matrix rotation is an easy breast-preserving technique for treating breast cancer located in the upper/upper inner quadrant of the breast that requires a relatively wide excision. With this technique, a larger breast tumor could be removed without compromising the breast appearance.

  19. Clustering of Emerging Flux

    Ruzmaikin, A.

    1997-01-01

    Observations show that newly emerging flux tends to appear on the Solar surface at sites where there is flux already. This results in clustering of solar activity. Standard dynamo theories do not predict this effect.

  20. Upper Gastrointestinal (GI) Series

    ... standard barium upper GI series, which uses only barium a double-contrast upper GI series, which uses both air and ... evenly coat your upper GI tract with the barium. If you are having a double-contrast study, you will swallow gas-forming crystals that ...

  1. Upper airway resistance syndrome.

    Montserrat, J M; Badia, J R

    1999-03-01

    This article reviews the clinical picture, diagnosis and management of the upper airway resistance syndrome (UARS). Presently, there is not enough data on key points like the frequency of UARS and the morbidity associated with this condition. Furthermore, the existence of LIARS as an independent sleep disorder and its relation with snoring and obstructive events is in debate. The diagnosis of UARS is still a controversial issue. The technical limitations of the classic approach to monitor airflow with thermistors and inductance plethysmography, as well as the lack of a precise definition of hypopnea, may have led to a misinterpretation of UARS as an independent diagnosis from the sleep apnea/hypopnea syndrome. The diagnosis of this syndrome can be missed using a conventional polysomnographic setting unless appropriate techniques are applied. The use of an esophageal balloon to monitor inspiratory effort is currently the gold standard. However, other sensitive methods such as the use of a pneumotachograph and, more recently, nasal cannula/pressure transducer systems or on-line monitoring of respiratory impedance with the forced oscillation technique may provide other interesting possibilities. Recognition and characterization of this subgroup of patients within sleep breathing disorders is important because they are symptomatic and may benefit from treatment. Management options to treat UARS comprise all those currently available for sleep apnea/hypopnea syndrome (SAHS). However, the subset of patients classically identified as LIARS that exhibit skeletal craneo-facial abnormalities might possibly obtain further benefit from maxillofacial surgery.

  2. FILAMENT INTERACTION MODELED BY FLUX ROPE RECONNECTION

    Toeroek, T.; Chandra, R.; Pariat, E.; Demoulin, P.; Schmieder, B.; Aulanier, G.; Linton, M. G.; Mandrini, C. H.

    2011-01-01

    Hα observations of solar active region NOAA 10501 on 2003 November 20 revealed a very uncommon dynamic process: during the development of a nearby flare, two adjacent elongated filaments approached each other, merged at their middle sections, and separated again, thereby forming stable configurations with new footpoint connections. The observed dynamic pattern is indicative of 'slingshot' reconnection between two magnetic flux ropes. We test this scenario by means of a three-dimensional zero β magnetohydrodynamic simulation, using a modified version of the coronal flux rope model by Titov and Demoulin as the initial condition for the magnetic field. To this end, a configuration is constructed that contains two flux ropes which are oriented side-by-side and are embedded in an ambient potential field. The choice of the magnetic orientation of the flux ropes and of the topology of the potential field is guided by the observations. Quasi-static boundary flows are then imposed to bring the middle sections of the flux ropes into contact. After sufficient driving, the ropes reconnect and two new flux ropes are formed, which now connect the former adjacent flux rope footpoints of opposite polarity. The corresponding evolution of filament material is modeled by calculating the positions of field line dips at all times. The dips follow the morphological evolution of the flux ropes, in qualitative agreement with the observed filaments.

  3. Effects of coronal regions on the x-ray flux and ionization conditions in the winds of ob supergiants and of stars

    Cassinelli, J.P.; Olson, G.L.

    1979-01-01

    The anomalously strong O VI and N V lines in O stars and the C IV lines in B supergiants may be due to Auger ionization by X-rays from a thin coronal zone at the base of the cool stellar winds. We determine the size of a corona that is necessary to produce the overall ionization conditions in zeta Pup as has been deduced by Olson from line profile analysis. In the ionization balance calculations we account for diffuse radiation field in the wind and for the large optical depths in the He II continuum due to radiative and Auger ionization edges of abundant elements. The X-ray flux transmitted through the wind is calculated and compared with upper limits derived for upper limits derived for zeta Pup observations from ANS and Uhuru satellites. It is found that a coronal zone with a temperature of 5x10 6 K and a volume emission measure of 10 58 cm -3 can produce the required ionization in a wind having a temperature of 30,000--35,000 K. The emergent X-ray flux bears little resemblance to the coronal emissivity because of the opacity of the wind. The X-ray flux nearly reaches the upper limits derived from the ANS observations and, at several energy bands, should be detectable by the HEAO B satellite. A simplified analysis of the Auger ionization process is developed and applied to other Of and OB supergiants. We find that the model can explain the presence of C IV and Si IV in supergaints with effective temperatures as low as 12,000 K and can explain the appearance of O VI and N V lines in early type supergiants as late as BO.5 and B2, respectively

  4. SMM observations of gamma-ray transients. 2: A search for gamma-ray lines between 400 and 600 keV from the Crab Nebula

    Harris, Michael J.; Share, Gerald H.; Leising, Mark D.

    1994-01-01

    We have search spectra obtained by the Solar Maximum Mission Gamma-Ray Spectrometer during 1981-1988 for evidence of transient gamma-ray lines from the Crab Nebula which have been reported by previous experiments at energies 400-460 keV and 539 keV. We find no evidence for significant emission in any of these lines on time scales between aproximately 1 day and approximately 1 yr. Our 3 sigma upper limits on the transient flux during 1 d intervals are approximately equal to 2.2 x 10(exp -3) photons/sq cm/s for narrow lines at any energy, and approximately equal to 2.9 x 10(exp -3) photons/sq cm/s for the 539 keV line if it is as broad as 42 keV Full Width at Half Maximum (FWHM). We also searched our data during the approximately 5 hr period on 1981 June 6 during which Owens, Myers, & Thompson (1985) reported a strong line at 405 keV. We detected no line down to a 3 upper sigma limit of 3.3 x 10(exp -3) photons/sq cm/s in disagreement with the flux 7.2 +/- 2.1 x 10(exp -3) photos/sq cm/s measured by Owens et al.

  5. Effect of Ca doping on thermally activated flux flow in the ...

    Administrator

    attracted much attention.10,11 Resistivity measurements under magnetic fields ... The flux line dynamics can be divided into three regimes (i) flux flow, J > Jc; .... energy dissipation occurs when the driving Lorentz force is increased with the ...

  6. 2D heat flux pattern in ASDEX upgrade L-mode with magnetic perturbation

    Faitsch, Michael; Sieglin, Bernhard; Eich, Thomas; Herrmann, Albrecht; Suttrop, Wolfgang [Max-Planck-Institute for Plasma Physics, Boltzmannstr. 2, D-85748 Garching (Germany); Collaboration: the ASDEDX Upgrade Team

    2016-07-01

    A future fusion reactor is likely to operate in high confinement mode (H-mode). This mode is associated with a periodic instability at the plasma edge that expels particles and energy. This instability is called edge localized mode (ELM). External magnetic perturbation (MP) is one technique that is thought to be able to mitigate or even suppress large ELMs in next step fusion devices such as ITER, where the ELM induced heat load for unmitigated ELMs might limit the lifetime of the divertor. Applying an external magnetic perturbation breaks the axisymmetry and leads to a 2D steady state heat flux pattern at the divertor. The ASDEX Upgrade tokamak is equipped with 16 perturbation coils, 8 above (upper row) and 8 below (lower row) the outer mid plane, toroidal equally distributed. A high resolution infra red system is measuring the heat flux at the outer target at a fixed toroidal position with a resolution of around 0.6 mm. In order to measure the 2D structure a slow rotation of the MP field was applied (1 Hz) with a toroidal mode number n=2. The differential phase between the upper and lower row was changed to investigate the effect of the alignment with the field lines at the edge. The density was varied to study the density dependence of the heat transport with applied external MP and compare it to the axisymmetric scenario.

  7. Compact neutron flux monitor

    Madhavi, V.; Phatak, P.R.; Bahadur, C.; Bayala, A.K.; Jakati, R.K.; Sathian, V.

    2003-01-01

    Full text: A compact size neutron flux monitor has been developed incorporating standard boards developed for smart radiation monitors. The sensitivity of the monitors is 0.4cps/nV. It has been tested up to 2075 nV flux with standard neutron sources. It shows convincing results even in high flux areas like 6m away from the accelerator in RMC (Parel) for 106/107 nV. These monitors have a focal and remote display, alarm function with potential free contacts for centralized control and additional provision of connectivity via RS485/Ethernet. This paper describes the construction, working and results of the above flux monitor

  8. The Solar-flux Third Granulation Signature

    Gray, David F.; Oostra, Benjamin

    2018-01-01

    The velocity shifts of spectral lines as a function of line strength, so-called the third signature of granulation, are investigated using three published solar-flux atlases. We use flux atlases because we wish to treat the Sun as a star, against which stellar observations can be compared and judged. The atlases are critiqued and compared to the lower-resolution observations taken with the Elginfield stellar spectrograph. Third-signature plots are constructed for the 6020–6340 Å region. No dependence on excitation potential or wavelength is found over this wavelength span. The shape of the plots from the three solar atlases is essentially the same, with rms line-core velocity differences of 30–35 m s‑1. High-resolution atlas data are degraded to the level of the Elginfield spectrograph and compared to direct observations taken with that spectrograph. The line-core velocities show good agreement, with rms differences of 38 m s‑1. A new standard curve is derived and compared with the previously published one. Only small differences in shape are found, but a significant (+97 m s‑1) change in the zero point is indicated. The bisector of the Fe I 6253 line is mapped onto the third-signature plots and flux deficits are derived, which measure the granule/lane flux imbalance. The lower spectral resolution lowers the flux deficit area slightly and moves the peak of the deficit 0.3–0.5 km s‑1 toward higher velocities. These differences, while significant, are not large compared to measurement errors for stellar data.

  9. A finite element calculation of flux pumping

    Campbell, A. M.

    2017-12-01

    A flux pump is not only a fascinating example of the power of Faraday’s concept of flux lines, but also an attractive way of powering superconducting magnets without large electronic power supplies. However it is not possible to do this in HTS by driving a part of the superconductor normal, it must be done by exceeding the local critical density. The picture of a magnet pulling flux lines through the material is attractive, but as there is no direct contact between flux lines in the magnet and vortices, unless the gap between them is comparable to the coherence length, the process must be explicable in terms of classical electromagnetism and a nonlinear V-I characteristic. In this paper a simple 2D model of a flux pump is used to determine the pumping behaviour from first principles and the geometry. It is analysed with finite element software using the A formulation and FlexPDE. A thin magnet is passed across one or more superconductors connected to a load, which is a large rectangular loop. This means that the self and mutual inductances can be calculated explicitly. A wide strip, a narrow strip and two conductors are considered. Also an analytic circuit model is analysed. In all cases the critical state model is used, so the flux flow resistivity and dynamic resistivity are not directly involved, although an effective resistivity appears when J c is exceeded. In most of the cases considered here is a large gap between the theory and the experiments. In particular the maximum flux transferred to the load area is always less than the flux of the magnet. Also once the threshold needed for pumping is exceeded the flux in the load saturates within a few cycles. However the analytic circuit model allows a simple modification to allow for the large reduction in I c when the magnet is over a conductor. This not only changes the direction of the pumped flux but leads to much more effective pumping.

  10. Nonvariceal upper gastrointestinal bleeding

    Burke, Stephen J.; Weldon, Derik; Sun, Shiliang; Golzarian, Jafar

    2007-01-01

    Nonvariceal upper gastrointestinal bleeding (NUGB) remains a major medical problem even after advances in medical therapy with gastric acid suppression and cyclooxygenase (COX-2) inhibitors. Although the incidence of upper gastrointestinal bleeding presenting to the emergency room has slightly decreased, similar decreases in overall mortality and rebleeding rate have not been experienced over the last few decades. Many causes of upper gastrointestinal bleeding have been identified and will be reviewed. Endoscopic, radiographic and angiographic modalities continue to form the basis of the diagnosis of upper gastrointestinal bleeding with new research in the field of CT angiography to diagnose gastrointestinal bleeding. Endoscopic and angiographic treatment modalities will be highlighted, emphasizing a multi-modality treatment plan for upper gastrointestinal bleeding. (orig.)

  11. Nonvariceal upper gastrointestinal bleeding

    Burke, Stephen J.; Weldon, Derik; Sun, Shiliang [University of Iowa, Department of Radiology, Iowa, IA (United States); Golzarian, Jafar [University of Iowa, Department of Radiology, Iowa, IA (United States); University of Iowa, Department of Radiology, Carver College of Medicine, Iowa, IA (United States)

    2007-07-15

    Nonvariceal upper gastrointestinal bleeding (NUGB) remains a major medical problem even after advances in medical therapy with gastric acid suppression and cyclooxygenase (COX-2) inhibitors. Although the incidence of upper gastrointestinal bleeding presenting to the emergency room has slightly decreased, similar decreases in overall mortality and rebleeding rate have not been experienced over the last few decades. Many causes of upper gastrointestinal bleeding have been identified and will be reviewed. Endoscopic, radiographic and angiographic modalities continue to form the basis of the diagnosis of upper gastrointestinal bleeding with new research in the field of CT angiography to diagnose gastrointestinal bleeding. Endoscopic and angiographic treatment modalities will be highlighted, emphasizing a multi-modality treatment plan for upper gastrointestinal bleeding. (orig.)

  12. Primary cosmic ray flux

    Stanev, Todor

    2001-05-01

    We discuss the primary cosmic ray flux from the point of view of particle interactions and production of atmospheric neutrinos. The overall normalization of the cosmic ray flux and its time variations and site dependence are major ingredients of the atmospheric neutrino predictions and the basis for the derivation of the neutrino oscillation parameters.

  13. Heat flux microsensor measurements

    Terrell, J. P.; Hager, J. M.; Onishi, S.; Diller, T. E.

    1992-01-01

    A thin-film heat flux sensor has been fabricated on a stainless steel substrate. The thermocouple elements of the heat flux sensor were nickel and nichrome, and the temperature resistance sensor was platinum. The completed heat flux microsensor was calibrated at the AEDC radiation facility. The gage output was linear with heat flux with no apparent temperature effect on sensitivity. The gage was used for heat flux measurements at the NASA Langley Vitiated Air Test Facility. Vitiated air was expanded to Mach 3.0 and hydrogen fuel was injected. Measurements were made on the wall of a diverging duct downstream of the injector during all stages of the hydrogen combustion tests. Because the wall and the gage were not actively cooled, the wall temperature reached over 1000 C (1900 F) during the most severe test.

  14. Metabolic flux analysis of the hydrogen production potential in Synechocystis sp. PCC6803

    Navarro, E. [Departamento de Lenguajes y Ciencias de la Computacion, Campus de Teatrinos, Universidad de Malaga, 29071 Malaga (Spain); Montagud, A.; Fernandez de Cordoba, P.; Urchueguia, J.F. [Instituto Universitario de Matematica Pura y Aplicada, Universidad Politecnica de Valencia, Camino de Vera 14, 46022 Valencia (Spain)

    2009-11-15

    Hydrogen is a promising energy vector; however, finding methods to produce it from renewable sources is essential to allow its wide-scale use. In that line, biological hydrogen production, although it is considered as a possible alternative, requires substantial improvements to overcome its present low yields. In that direction, genetic manipulation probably will play a central role and from that point of view metabolic flux analysis (MFA) constitutes an important tool to guide a priori most suitable genetic modifications oriented to a hydrogen yield increase. In this work MFA has been applied to analyze hydrogen photoproduction of Synechocystis sp. PCC6803. Flux analysis was carried out based on literature data and several basic fluxes were estimated in different growing conditions of the system. From this analysis, an upper limit for hydrogen photoproduction has been determined indicating a wide margin for improvement. MFA was also used to find a feasible operating space for hydrogen production, which avoids oxygen inhibition, one of the most important limitations to make hydrogen production cost effective. In addition, a set of biotechnological strategies are proposed that would be consistent with the performed mathematical analysis. (author)

  15. Ultraviolet photometry from the orbiting astronomical observatory. XVI - The stellar Lyman-alpha absorption line

    Savage, B. D.; Panek, R. J.

    1974-01-01

    The stellar Lyman-alpha line at 1216 A was observed in 29 lightly reddened stars of spectral type B2.5 to B9 by a far-UV spectrophotometer on OAO-2. The equivalent widths obtained range from 15 A at type B2.5 to 65 A at type B8; in the late-B stars, the L-alpha line removes 2 to 3% of the total stellar flux. In this sampling, the strength of the L-alpha line correlates well with measures of the Balmer discontinuity and Balmer line strengths; luminosity classification does not seem to affect the line strength. The observed line widths also agree with the predictions of Mihala's grid of non-LTE model atmospheres. In some cases, the L-alpha line influences the interstellar column densities reported in the interstellar OAO-2 L-alpha survey. Hence, these data toward lightly reddened B2 and B1.5 stars should be regarded as upper limits only.

  16. Observation of a Coulomb flux tube

    Greensite, Jeff; Chung, Kristian

    2018-03-01

    In Coulomb gauge there is a longitudinal color electric field associated with a static quark-antiquark pair. We have measured the spatial distribution of this field, and find that it falls off exponentially with transverse distance from a line joining the two quarks. In other words there is a Coulomb flux tube, with a width that is somewhat smaller than that of the minimal energy flux tube associated with the asymptotic string tension. A confinement criterion for gauge theories with matter fields is also proposed.

  17. ACA Federal Upper Limits

    U.S. Department of Health & Human Services — Affordable Care Act Federal Upper Limits (FUL) based on the weighted average of the most recently reported monthly average manufacturer price (AMP) for...

  18. Melted flux liquids in high-Tc superconductors

    Nelson, D.R.

    1989-01-01

    A theory of the entangles flux liquids which arise in the new high-T c superconductors is reviewed. New physics appears because of the weak interplanar couplings and high critical temperatures in these materials. Flux line wandering melts the conventional Abrikosov flux lattice over large portions of the phase diagram and leads to a novel entangled vortex state. The authors suggest that a heavily entangled flux liquid could exhibit glassy behavior on experimental time scales, in analogy with viscoelastic behavior in dense polymer melts

  19. Upper gastrointestinal bleeding.

    Feinman, Marcie; Haut, Elliott R

    2014-02-01

    Upper gastrointestinal (GI) bleeding remains a commonly encountered diagnosis for acute care surgeons. Initial stabilization and resuscitation of patients is imperative. Stable patients can have initiation of medical therapy and localization of the bleeding, whereas persistently unstable patients require emergent endoscopic or operative intervention. Minimally invasive techniques have surpassed surgery as the treatment of choice for most upper GI bleeding. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. On the Evolution of the Inner Disk Radius with Flux in the Neutron Star Low-mass X-Ray Binary Serpens X-1

    Chiang, Chia - Ying; Morgan, Robert A.; Cackett, Edward M.; Miller, Jon M.; Bhattacharyya, Sudip; Strohmayer, Tod E.

    2016-01-01

    We analyze the latest Suzaku observation of the bright neutron star (NS) low-mass X-ray binary Serpens X-1 taken in 2013 October and 2014 April. The observation was taken using the burst mode and only suffered mild pile-up effects. A broad iron line is clearly detected in the X-ray spectrum. We test different models and find that the iron line is asymmetric and best interpreted by relativistic reflection. The relativistically broadened iron line is generally believed to originate from the innermost regions of the accretion disk, where strong gravity causes a series of special and general relativistic effects. The iron line profile indicates an inner radius of approx. 8 R(sub G), which gives an upper limit on the size of the NS. The asymmetric iron line has been observed in a number of previous observations, which gives several inner radius measurements at different flux states. We find that the inner radius of Serpens X-1 does not evolve significantly over the range of L/L(sub Edd) approx. 0.4-0.6, and the lack of flux dependence of the inner radius implies that the accretion disk may be truncated outside of the innermost stable circular orbit by the boundary layer, rather than the stellar magnetic field.

  1. ON THE EVOLUTION OF THE INNER DISK RADIUS WITH FLUX IN THE NEUTRON STAR LOW-MASS X-RAY BINARY SERPENS X-1

    Chiang, Chia-Ying; Morgan, Robert A.; Cackett, Edward M. [Department of Physics and Astronomy, Wayne State University, 666 W. Hancock, Detroit, MI 48202 (United States); Miller, Jon M. [Department of Astronomy, The University of Michigan, 500 Church Street, Ann Arbor, MI 48109-1046 (United States); Bhattacharyya, Sudip [Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Mumbai 400005 (India); Strohmayer, Tod E., E-mail: ft8320@wayne.edu [X-Ray Astrophysics Lab, Astrophysics Science Division, NASA’s Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2016-11-01

    We analyze the latest Suzaku observation of the bright neutron star (NS) low-mass X-ray binary Serpens X-1 taken in 2013 October and 2014 April. The observation was taken using the burst mode and only suffered mild pile-up effects. A broad iron line is clearly detected in the X-ray spectrum. We test different models and find that the iron line is asymmetric and best interpreted by relativistic reflection. The relativistically broadened iron line is generally believed to originate from the innermost regions of the accretion disk, where strong gravity causes a series of special and general relativistic effects. The iron line profile indicates an inner radius of ∼8 R {sub G}, which gives an upper limit on the size of the NS. The asymmetric iron line has been observed in a number of previous observations, which gives several inner radius measurements at different flux states. We find that the inner radius of Serpens X-1 does not evolve significantly over the range of L / L {sub Edd} ∼ 0.4–0.6, and the lack of flux dependence of the inner radius implies that the accretion disk may be truncated outside of the innermost stable circular orbit by the boundary layer, rather than the stellar magnetic field.

  2. Continuous magnetic flux pump

    Hildebrandt, A. F.; Elleman, D. D.; Whitmore, F. C. (Inventor)

    1966-01-01

    A method and means for altering the intensity of a magnetic field by transposing flux from one location to the location desired fro the magnetic field are examined. The device described includes a pair of communicating cavities formed in a block of superconducting material, is dimensioned to be insertable into one of the cavities and to substantially fill the cavity. Magnetic flux is first trapped in the cavities by establishing a magnetic field while the superconducting material is above the critical temperature at which it goes superconducting. Thereafter, the temperature of the material is reduced below the critical value, and then the exciting magnetic field may be removed. By varying the ratios of the areas of the two cavities, it is possible to produce a field having much greater flux density in the second, smaller cavity, into which the flux transposed.

  3. Flux in Tallinn

    2004-01-01

    Rahvusvahelise elektroonilise kunsti sümpoosioni ISEA2004 klubiõhtu "Flux in Tallinn" klubis Bon Bon. Eestit esindasid Ropotator, Ars Intel Inc., Urmas Puhkan, Joel Tammik, Taavi Tulev (pseud. Wochtzchee). Klubiõhtu koordinaator Andres Lõo

  4. Flux shunts for undulators

    Hoyer, E.; Chin, J.; Hassenzahl, W.V.

    1993-05-01

    Undulators for high-performance applications in synchrotron-radiation sources and periodic magnetic structures for free-electron lasers have stringent requirements on the curvature of the electron's average trajectory. Undulators using the permanent magnet hybrid configuration often have fields in their central region that produce a curved trajectory caused by local, ambient magnetic fields such as those of the earth. The 4.6 m long Advanced Light Source (ALS) undulators use flux shunts to reduce this effect. These flux shunts are magnetic linkages of very high permeability material connecting the two steel beams that support the magnetic structures. The shunts reduce the scalar potential difference between the supporting beams and carry substantial flux that would normally appear in the undulator gap. Magnetic design, mechanical configuration of the flux shunts and magnetic measurements of their effect on the ALS undulators are described

  5. Evidence for flux ropes in the earth's magnetotail

    Sibeck, D.G.

    1990-01-01

    Magnetic field reconnection is a fundamental process that occurs in the magnetotail during geomagnetic substorms. Some 2D reconnection models predict the formation of a plasmoid, or closed loop of magnetic field lines, in the noon-midnight meridional plane at those times. When the 3D magnetotail magnetic field is considered, it becomes clear that reconnection produces a flux rope with an axis transverse to the earth-sun line. Three signatures mark both 2D plasmoids and 3D flux ropes: (1) a bipolar magnetic field signature, (2) tailward flow of a hot plasma, and (3) convecting isotropic energetic particle distributions. Plasmoids and flux ropes may be distinguished by (4) the axial magnetic field that only flux ropes possess. All four signatures have been identified in near-earth, middle, and distant magnetotail observations, but their interpretation is disputed. Thus, the existence of magnetotail flux ropes remains a controversial subject. 59 refs

  6. Neutron flux monitor

    Oda, Naotaka.

    1993-01-01

    The device of the present invention greatly saves an analog processing section such as an analog filter and an analog processing circuit. That is, the device of the present invention comprises (1) a neutron flux detection means for detecting neutron fluxed in the reactor, (2) a digital filter means for dividing signals corresponding to the detected neutron fluxes into predetermined frequency band regions, (3) a calculation processing means for applying a calculation processing corresponding to the frequency band regions to the neutron flux detection signals divided by the digital filter means. With such a constitution, since the neutron detection signals are processed by the digital filter means, the accuracy is improved and the change for the property of the filter is facilitated. Further, when a neutron flux level is obtained, a calculation processing corresponding to the frequency band region can be conducted without the analog processing circuit. Accordingly, maintenance and accuracy are improved by greatly decreasing the number of parts. Further, since problems inherent to the analog circuit are solved, neutron fluxes are monitored at high reliability. (I.S.)

  7. Neutron flux monitoring device

    Shimazu, Yoichiro.

    1995-01-01

    In a neutron flux monitoring device, there are disposed a neutron flux measuring means for outputting signals in accordance with the intensity of neutron fluxes, a calculation means for calculating a self power density spectrum at a frequency band suitable to an object to be measured based on the output of the neutron flux measuring means, an alarm set value generation means for outputting an alarm set value as a comparative reference, and an alarm judging means for comparing the alarm set value with the outputted value of the calculation means to judge requirement of generating an alarm and generate an alarm in accordance with the result of the judgement. Namely, the time-series of neutron flux signals is put to fourier transformation for a predetermined period of time by the calculation means, and from each of square sums for real number component and imaginary number component for each of the frequencies, a self power density spectrum in the frequency band suitable to the object to be measured is calculated. Then, when the set reference value is exceeded, an alarm is generated. This can reliably prevent generation of erroneous alarm due to neutron flux noises and can accurately generate an alarm at an appropriate time. (N.H.)

  8. The emerging magnetic flux and the elementary eruptive phenomenon

    Mouradian, Z.; Martres, M.J.; Soru-Escaut, I.

    1983-01-01

    Observational studies before and during the flare start were made in Hα(3-lambda heliograph at Meudon Observatory) on a large sample of ''elementary'' flares, both on the disk and along the limb of the Sun. The concept of elementary eruptive phenomenon (EEP) is proposed to describe these observational data. The EEP may be considered as the basic element of complex flares which, then, are built up by the juxtaposition of several EEP. In the inferred scenario, the chromospheric eruptive phenomenon consists of two systems of loops: one cold - the surging arch - Tapprox.=10 4 K, the other hot - the flaring arch -, covering a temperature range up to 10 7 K. The footpoints of the two systems remain differentiated until extinction of the phenomenon; their behaviour over time differs also. The surging arch (the magnetic flux emergence) rises first progressively in the solar atmosphere and the upper part of the loop is heated to coronal temperatures. The classical surge which is observed in the center of the Hα line, after the flash phase of the flare, is only the late development of the surging arch. The flaring arch originates from a pre-existing low loop, which is also to rise in the solar atmosphere. These two systems coexist and may combine to form such physical characteristics as mass motion, expansion and post-flash phase. (orig.)

  9. Vertical divergence of fogwater fluxes above a spruce forest

    Burkard, R.; Eugster, W.; Wrzesinsky, T.; Klemm, O.

    Two almost identical eddy covariance measurement setups were used to measure the fogwater fluxes to a forest ecosystem in the "Fichtelgebirge" mountains (Waldstein research site, 786 m a.s.l.) in Germany. During the first experiment, an intercomparison was carried out with both setups running simultaneously at the same measuring height on a meteorological tower, 12.5 m above the forest canopy. The results confirmed a close agreement of the turbulent fluxes between the two setups, and allowed to intercalibrate liquid water content (LWC) and gravitational fluxes. During the second experiment, the setups were mounted at a height of 12.5 and 3 m above the canopy, respectively. For the 22 fog events, a persistent negative flux divergence was observed with a greater downward flux at the upper level. To extrapolate the turbulent liquid water fluxes measured at height z to the canopy of height hc, a conversion factor 1/[1+0.116( z- hc)] was determined. For the fluxes of nonvolatile ions, no such correction is necessary since the net evaporation of the fog droplets appears to be the primary cause of the vertical flux divergence. Although the net evaporation reduces the liquid water flux reaching the canopy, it is not expected to change the absolute amount of ions dissolved in fogwater.

  10. Triode for magnetic flux quanta.

    Vlasko-Vlasov, Vitalii; Colauto, Fabiano; Benseman, Timothy; Rosenmann, Daniel; Kwok, Wai-Kwong

    We designed a magnetic vortex triode using an array of closely spaced soft magnetic Py strips on top of a Nb superconducting film. The strips act similar to the grid electrode in an electronic triode, where the electron flow is regulated by the grid potential. In our case, we tune the vortex motion by the magnetic charge potential of the strip edges, using a small magnetic field rotating in the film plane. The magnetic charges emerging at the stripe edges and proportional to the magnetization component perpendicular to the edge direction, form linear potential barriers or valleys for vortex motion in the superconducting layer. We directly imaged the normal flux penetration into the Py/Nb films and observed retarded or accelerated entry of the normal vortices depending on the in-plane magnetization direction in the stripes. The observed flux behavior is explained by interactions between magnetically charged lines and magnetic monopoles of vortices similar to those between electrically charged strings and point charges. We discuss the possibility of using our design for manipulation of individual vortices in high-speed, low-power superconducting electronic circuits. This work was supported by the U.S. DOE, Office of Science, Materials Sciences and Engineering Division, and Office of BES (contract DE-AC02-06CH11357). F. Colauto thanks the Sao Paulo Research Foundation FAPESP (Grant No. 2015/06.085-3).

  11. Muon Flux Limits for Majorana Dark Matter Particles

    Belotsky, Konstantin; Khlopov, Maxim; Kouvaris, Christoforos

    2009-01-01

    We analyze the effects of capture of dark matter (DM) particles, with successive annihilations, predicted in the minimal walking technicolor model (MWT) by the Sun and the Earth. We show that the Super-Kamiokande (SK) upper limit on excessive muon flux disfavors the mass interval between 100-200 Ge...

  12. The Open Flux Problem

    Linker, J. A.; Caplan, R. M.; Downs, C.; Riley, P.; Mikic, Z.; Lionello, R.; Henney, C. J.; Arge, C. N.; Liu, Y.; Derosa, M. L.; Yeates, A.; Owens, M. J.

    2017-10-01

    The heliospheric magnetic field is of pivotal importance in solar and space physics. The field is rooted in the Sun’s photosphere, where it has been observed for many years. Global maps of the solar magnetic field based on full-disk magnetograms are commonly used as boundary conditions for coronal and solar wind models. Two primary observational constraints on the models are (1) the open field regions in the model should approximately correspond to coronal holes (CHs) observed in emission and (2) the magnitude of the open magnetic flux in the model should match that inferred from in situ spacecraft measurements. In this study, we calculate both magnetohydrodynamic and potential field source surface solutions using 14 different magnetic maps produced from five different types of observatory magnetograms, for the time period surrounding 2010 July. We have found that for all of the model/map combinations, models that have CH areas close to observations underestimate the interplanetary magnetic flux, or, conversely, for models to match the interplanetary flux, the modeled open field regions are larger than CHs observed in EUV emission. In an alternative approach, we estimate the open magnetic flux entirely from solar observations by combining automatically detected CHs for Carrington rotation 2098 with observatory synoptic magnetic maps. This approach also underestimates the interplanetary magnetic flux. Our results imply that either typical observatory maps underestimate the Sun’s magnetic flux, or a significant portion of the open magnetic flux is not rooted in regions that are obviously dark in EUV and X-ray emission.

  13. The Open Flux Problem

    Linker, J. A.; Caplan, R. M.; Downs, C.; Riley, P.; Mikic, Z.; Lionello, R. [Predictive Science Inc., 9990 Mesa Rim Road, Suite 170, San Diego, CA 92121 (United States); Henney, C. J. [Air Force Research Lab/Space Vehicles Directorate, 3550 Aberdeen Avenue SE, Kirtland AFB, NM (United States); Arge, C. N. [Science and Exploration Directorate, NASA/GSFC, Greenbelt, MD 20771 (United States); Liu, Y. [W. W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305 (United States); Derosa, M. L. [Lockheed Martin Solar and Astrophysics Laboratory, 3251 Hanover Street B/252, Palo Alto, CA 94304 (United States); Yeates, A. [Department of Mathematical Sciences, Durham University, Durham, DH1 3LE (United Kingdom); Owens, M. J., E-mail: linkerj@predsci.com [Space and Atmospheric Electricity Group, Department of Meteorology, University of Reading, Earley Gate, P.O. Box 243, Reading RG6 6BB (United Kingdom)

    2017-10-10

    The heliospheric magnetic field is of pivotal importance in solar and space physics. The field is rooted in the Sun’s photosphere, where it has been observed for many years. Global maps of the solar magnetic field based on full-disk magnetograms are commonly used as boundary conditions for coronal and solar wind models. Two primary observational constraints on the models are (1) the open field regions in the model should approximately correspond to coronal holes (CHs) observed in emission and (2) the magnitude of the open magnetic flux in the model should match that inferred from in situ spacecraft measurements. In this study, we calculate both magnetohydrodynamic and potential field source surface solutions using 14 different magnetic maps produced from five different types of observatory magnetograms, for the time period surrounding 2010 July. We have found that for all of the model/map combinations, models that have CH areas close to observations underestimate the interplanetary magnetic flux, or, conversely, for models to match the interplanetary flux, the modeled open field regions are larger than CHs observed in EUV emission. In an alternative approach, we estimate the open magnetic flux entirely from solar observations by combining automatically detected CHs for Carrington rotation 2098 with observatory synoptic magnetic maps. This approach also underestimates the interplanetary magnetic flux. Our results imply that either typical observatory maps underestimate the Sun’s magnetic flux, or a significant portion of the open magnetic flux is not rooted in regions that are obviously dark in EUV and X-ray emission.

  14. Flux ropes and 3D dynamics in the relaxation scaling experiment

    Intrator, T P; Feng, Y; Weber, T E; Swan, H O; Sun, X; Dorf, L; Sears, J A

    2013-01-01

    Flux ropes form basic building blocks for magnetic dynamics in many plasmas, are macroscopic analogues of magnetic field lines, and are irreducibly three dimensional (3D). We have used the relaxation scaling experiment (RSX) to study flux ropes, and have found many new features involving 3D dynamics, kink instability driven reconnection, nonlinearly stable but kinking flux ropes, and large flows. (paper)

  15. Behind Lines

    Dayer, Carolina

    2017-01-01

    translations. The plan drawing, understood as the Vitruvian footprint—ichnographia—of the building, is a mark metonymically connected with the reality of architecture. Through a process of multiple methodological transfers and translations, the plan drawing operates as a continuum in flux that subsequently...

  16. CURRENT BUILDUP IN EMERGING SERPENTINE FLUX TUBES

    Pariat, E.; Masson, S.; Aulanier, G.

    2009-01-01

    The increase of magnetic flux in the solar atmosphere during active-region formation involves the transport of the magnetic field from the solar convection zone through the lowest layers of the solar atmosphere, through which the plasma β changes from >1 to <1 with altitude. The crossing of this magnetic transition zone requires the magnetic field to adopt a serpentine shape also known as the sea-serpent topology. In the frame of the resistive flux-emergence model, the rising of the magnetic flux is believed to be dynamically driven by a succession of magnetic reconnections which are commonly observed in emerging flux regions as Ellerman bombs. Using a data-driven, three-dimensional (3D) magnetohydrodynamic numerical simulation of flux emergence occurring in active region 10191 on 2002 November 16-17, we study the development of 3D electric current sheets. We show that these currents buildup along the 3D serpentine magnetic-field structure as a result of photospheric diverging horizontal line-tied motions that emulate the observed photospheric evolution. We observe that reconnection can not only develop following a pinching evolution of the serpentine field line, as usually assumed in two-dimensional geometry, but can also result from 3D shearing deformation of the magnetic structure. In addition, we report for the first time on the observation in the UV domain with the Transition Region and Coronal Explorer (TRACE) of extremely transient loop-like features, appearing within the emerging flux domain, which link several Ellermam bombs with one another. We argue that these loop transients can be explained as a consequence of the currents that build up along the serpentine magnetic field.

  17. Quantum information storage using tunable flux qubits

    Steffen, Matthias; Brito, Frederico; DiVincenzo, David; Farinelli, Matthew; Keefe, George; Ketchen, Mark; Kumar, Shwetank; Milliken, Frank; Rothwell, Mary Beth; Rozen, Jim; Koch, Roger H, E-mail: msteffe@us.ibm.co [IBM Watson Research Center, Yorktown Heights, NY 10598 (United States)

    2010-02-10

    We present details and results for a superconducting quantum bit (qubit) design in which a tunable flux qubit is coupled strongly to a transmission line. Quantum information storage in the transmission line is demonstrated with a dephasing time of T{sub 2}approx2.5 mus. However, energy lifetimes of the qubit are found to be short (approx10 ns) and not consistent with predictions. Several design and material changes do not affect qubit coherence times. In order to determine the cause of these short coherence times, we fabricated standard flux qubits based on a design which was previously successfully used by others. Initial results show significantly improved coherence times, possibly implicating losses associated with the large size of our qubit. (topical review)

  18. The drift-flux correlation package MDS

    Hoeld, A.

    2001-01-01

    Based on the SONNENBURG drift-flux correlation, developed at GRS/Garching (Germany), a comprehensive drift-flux correlation package (MDS) has been established. Its aim is to support thermal-hydraulic mixture-fluid models, models being used for the simulation of the steady state and transient behaviour of characteristic thermal-hydraulic parameters of single- or two-phase fluids flowing along coolant channels of different types (being, e.g., parts of NPP-s, steam generators etc.). The characteristic properties of this package with respect to the behaviour at co- and counter-current flow, its inverse solutions needed for steady state simulations, its behaviour when approaching the lower or upper boundary of a two-phase region, its verification and behaviour with respect to other correlations will be discussed. An adequate driver code, MDSDRI, has been established too, allowing to test the package very thoroughly out of the complex thermal-hydraulic codes. (author)

  19. The drift-flux correlation package MDS

    Hoeld, A. [Bernaysstr. 16A, Munich, F.R. (Germany)

    2001-07-01

    Based on the SONNENBURG drift-flux correlation, developed at GRS/Garching (Germany), a comprehensive drift-flux correlation package (MDS) has been established. Its aim is to support thermal-hydraulic mixture-fluid models, models being used for the simulation of the steady state and transient behaviour of characteristic thermal-hydraulic parameters of single- or two-phase fluids flowing along coolant channels of different types (being, e.g., parts of NPP-s, steam generators etc.). The characteristic properties of this package with respect to the behaviour at co- and counter-current flow, its inverse solutions needed for steady state simulations, its behaviour when approaching the lower or upper boundary of a two-phase region, its verification and behaviour with respect to other correlations will be discussed. An adequate driver code, MDSDRI, has been established too, allowing to test the package very thoroughly out of the complex thermal-hydraulic codes. (author)

  20. Meromorphic flux compactification

    Damian, Cesar [Departamento de Ingeniería Mecánica, Universidad de Guanajuato,Carretera Salamanca-Valle de Santiago Km 3.5+1.8 Comunidad de Palo Blanco,Salamanca (Mexico); Loaiza-Brito, Oscar [Departamento de Física, Universidad de Guanajuato,Loma del Bosque No. 103 Col. Lomas del Campestre C.P 37150 León, Guanajuato (Mexico)

    2017-04-26

    We present exact solutions of four-dimensional Einstein’s equations related to Minkoswki vacuum constructed from Type IIB string theory with non-trivial fluxes. Following https://www.doi.org/10.1007/JHEP02(2015)187; https://www.doi.org/10.1007/JHEP02(2015)188 we study a non-trivial flux compactification on a fibered product by a four-dimensional torus and a two-dimensional sphere punctured by 5- and 7-branes. By considering only 3-form fluxes and the dilaton, as functions on the internal sphere coordinates, we show that these solutions correspond to a family of supersymmetric solutions constructed by the use of G-theory. Meromorphicity on functions constructed in terms of fluxes and warping factors guarantees that flux and 5-brane contributions to the scalar curvature vanish while fulfilling stringent constraints as tadpole cancelation and Bianchi identities. Different Einstein’s solutions are shown to be related by U-dualities. We present three supersymmetric non-trivial Minkowski vacuum solutions and compute the corresponding soft terms. We also construct a non-supersymmetric solution and study its stability.

  1. Meromorphic flux compactification

    Damian, Cesar; Loaiza-Brito, Oscar

    2017-01-01

    We present exact solutions of four-dimensional Einstein’s equations related to Minkoswki vacuum constructed from Type IIB string theory with non-trivial fluxes. Following https://www.doi.org/10.1007/JHEP02(2015)187; https://www.doi.org/10.1007/JHEP02(2015)188 we study a non-trivial flux compactification on a fibered product by a four-dimensional torus and a two-dimensional sphere punctured by 5- and 7-branes. By considering only 3-form fluxes and the dilaton, as functions on the internal sphere coordinates, we show that these solutions correspond to a family of supersymmetric solutions constructed by the use of G-theory. Meromorphicity on functions constructed in terms of fluxes and warping factors guarantees that flux and 5-brane contributions to the scalar curvature vanish while fulfilling stringent constraints as tadpole cancelation and Bianchi identities. Different Einstein’s solutions are shown to be related by U-dualities. We present three supersymmetric non-trivial Minkowski vacuum solutions and compute the corresponding soft terms. We also construct a non-supersymmetric solution and study its stability.

  2. Flux Pinning in Superconductors

    Matsushita, Teruo

    2007-01-01

    The book covers the flux pinning mechanisms and properties and the electromagnetic phenomena caused by the flux pinning common for metallic, high-Tc and MgB2 superconductors. The condensation energy interaction known for normal precipitates or grain boundaries and the kinetic energy interaction proposed for artificial Nb pins in Nb-Ti, etc., are introduced for the pinning mechanism. Summation theories to derive the critical current density are discussed in detail. Irreversible magnetization and AC loss caused by the flux pinning are also discussed. The loss originally stems from the ohmic dissipation of normal electrons in the normal core driven by the electric field induced by the flux motion. The readers will learn why the resultant loss is of hysteresis type in spite of such mechanism. The influence of the flux pinning on the vortex phase diagram in high Tc superconductors is discussed, and the dependencies of the irreversibility field are also described on other quantities such as anisotropy of supercondu...

  3. Right upper quadrant pain

    Ralls, P.W.; Colletti, P.M.; Boswell, W.D. Jr.; Halls, J.M.

    1984-01-01

    Historically, assessment of acute right upper quadrant abdominal pain has been a considerable clinical challenge. While clinical findings and laboratory data frequently narrow the differential diagnosis, symptom overlap generally precludes definitive diagnosis among the various diseases causing acute right upper quadrant pain. Fortunately, the advent of newer diagnostic imaging modalities has greatly improved the rapidity and reliability of diagnosis in these patients. An additional challenge to the physician, with increased awareness of the importance of cost effectiveness in medicine, is to select appropriate diagnostic schema that rapidly establish accurate diagnoses in the most economical fashion possible. The dual goals of this discussion are to assess not only the accuracy of techniques used to evaluate patients with acute right upper quadrant pain, but also to seek out cost-effective, coordinated imaging techniques to achieve this goal

  4. Neutron flux monitoring device

    Goto, Yasushi; Mitsubori, Minehisa; Ohashi, Kazunori.

    1997-01-01

    The present invention provides a neutron flux monitoring device for preventing occurrence of erroneous reactor scram caused by the elevation of the indication of a start region monitor (SRM) due to a factor different from actual increase of neutron fluxes. Namely, judgement based on measured values obtained by a pulse counting method and a judgment based on measured values obtained by a Cambel method are combined. A logic of switching neutron flux measuring method to be used for monitoring, namely, switching to an intermediate region when both of the judgements are valid is adopted. Then, even if the indication value is elevated based on the Cambel method with no increase of the counter rate in a neutron source region, the switching to the intermediate region is not conducted. As a result, erroneous reactor scram such as 'shorter reactor period' can be avoided. (I.S.)

  5. CO2 flux from Javanese mud volcanism.

    Queißer, M; Burton, M R; Arzilli, F; Chiarugi, A; Marliyani, G I; Anggara, F; Harijoko, A

    2017-06-01

    Studying the quantity and origin of CO 2 emitted by back-arc mud volcanoes is critical to correctly model fluid-dynamical, thermodynamical, and geochemical processes that drive their activity and to constrain their role in the global geochemical carbon cycle. We measured CO 2 fluxes of the Bledug Kuwu mud volcano on the Kendeng Fold and thrust belt in the back arc of Central Java, Indonesia, using scanning remote sensing absorption spectroscopy. The data show that the expelled gas is rich in CO 2 with a volume fraction of at least 16 vol %. A lower limit CO 2 flux of 1.4 kg s -1 (117 t d -1 ) was determined, in line with the CO 2 flux from the Javanese mud volcano LUSI. Extrapolating these results to mud volcanism from the whole of Java suggests an order of magnitude total CO 2 flux of 3 kt d -1 , comparable with the expected back-arc efflux of magmatic CO 2 . After discussing geochemical, geological, and geophysical evidence we conclude that the source of CO 2 observed at Bledug Kuwu is likely a mixture of thermogenic, biogenic, and magmatic CO 2 , with faulting controlling potential pathways for magmatic fluids. This study further demonstrates the merit of man-portable active remote sensing instruments for probing natural gas releases, enabling bottom-up quantification of CO 2 fluxes.

  6. Flux Cancellation Leading to CME Filament Eruptions

    Popescu, Roxana M.; Panesar, Navdeep K.; Sterling, Alphonse C.; Moore, Ronald L.

    2016-01-01

    Solar filaments are strands of relatively cool, dense plasma magnetically suspended in the lower density hotter solar corona. They trace magnetic polarity inversion lines (PILs) in the photosphere below, and are supported against gravity at heights of up to approx.100 Mm above the chromosphere by the magnetic field in and around them. This field erupts when it is rendered unstable, often by magnetic flux cancellation or emergence at or near the PIL. We have studied the evolution of photospheric magnetic flux leading to ten observed filament eruptions. Specifically, we look for gradual magnetic changes in the neighborhood of the PIL prior to and during eruption. We use Extreme Ultraviolet (EUV) images from the Atmospheric Imaging Assembly (AIA), and magnetograms from the Helioseismic and Magnetic Imager (HMI), both on board the Solar Dynamics Observatory (SDO), to study filament eruptions and their photospheric magnetic fields. We examine whether flux cancellation or/and emergence leads to filament eruptions. We find that continuous flux cancellation was present at the PIL for many hours prior to each eruption. We present two CME-producing eruptions in detail and find the following: (a) the pre-eruption filament-holding core field is highly sheared and appears in the shape of a sigmoid above the PIL; (b) at the start of the eruption the opposite arms of the sigmoid reconnect in the middle above the site of (tether-cutting) flux cancellation at the PIL; (c) the filaments first show a slow-rise, followed by a fast-rise as they erupt. We conclude that these two filament eruptions result from flux cancellation in the middle of the sheared field, and thereafter evolve in agreement with the standard model for a CME/flare filament eruption from a closed bipolar magnetic field [flux cancellation (van Ballegooijen and Martens 1989 and Moore and Roumelrotis 1992) and runaway tether-cutting (Moore et. al 2001)].

  7. The Oceanic Flux Program: A three decade time-series of particle flux in the deep Sargasso Sea

    Weber, J. C.; Conte, M. H.

    2010-12-01

    The Oceanic Flux Program (OFP), 75 km SE of Bermuda, is the longest running time-series of its kind. Initiated in 1978, the OFP has produced an unsurpassed, nearly continuous record of temporal variability in deep ocean fluxes, with a >90% temporal coverage at 3200m depth. The OFP, in conjunction with the co-located Bermuda-Atlantic Time Series (BATS) and the Bermuda Testbed Mooring (BTM) time-series, has provided key observations enabling detailed assessment of how seasonal and non-seasonal variability in the deep ocean is linked with the overlying physical and biogeochemical environment. This talk will focus on the short-term flux variability that overlies the seasonal flux pattern in the Sargasso Sea, emphasizing episodic extreme flux events. Extreme flux events are responsible for much of the year-to-year variability in mean annual flux and are most often observed during early winter and late spring when surface stratification is weak or transient. In addition to biological phenomena (e.g. salp blooms), passage of productive meso-scale features such as eddies, which alter surface water mixing characteristics and surface export fluxes, may initiate some extreme flux events. Yet other productive eddies show a minimal influence on the deep flux, underscoring the importance of upper ocean ecosystem structure and midwater processes on the coupling between the surface ocean environment and deep fluxes. Using key organic and inorganic tracers, causative processes that influence deep flux generation and the strength of the coupling with the surface ocean environment can be identified.

  8. Atmospheric neutrino fluxes

    Honda, M.; Kasahara, K.; Hidaka, K.; Midorikawa, S.

    1990-02-01

    A detailed Monte Carlo simulation of neutrino fluxes of atmospheric origin is made taking into account the muon polarization effect on neutrinos from muon decay. We calculate the fluxes with energies above 3 MeV for future experiments. There still remains a significant discrepancy between the calculated (ν e +antiν e )/(ν μ +antiν μ ) ratio and that observed by the Kamiokande group. However, the ratio evaluated at the Frejus site shows a good agreement with the data. (author)

  9. High Line

    Kiib, Hans

    2015-01-01

    At just over 10 meters above street level, the High Line extends three kilometers through three districts of Southwestern Manhattan in New York. It consists of simple steel construction, and previously served as an elevated rail line connection between Penn Station on 34th Street and the many....... The High Line project has been carried out as part of an open conversion strategy. The result is a remarkable urban architectural project, which works as a catalyst for the urban development of Western Manhattan. The greater project includes the restoration and reuse of many old industrial buildings...

  10. Upper airway evaluation

    Hoffman, E.A.; Gefter, W.B.; Schnall, M.; Nordberg, J.; Listerud, J.; Lenkinski, R.E.

    1988-01-01

    The authors are evaluating upper-airway sleep disorders with magnetic resonance (MR) imaging and x-ray cine computed tomography (CT). Fixed structural anatomy is visualized with multisection spin-echo MR imaging, the dynamic component with cine CT. Unique aspects of the study are described in this paper

  11. World lines.

    Waser Jürgen; Fuchs Raphael; Ribicic Hrvoje; Schindler Benjamin; Blöschl Günther; Gröller Eduard

    2010-01-01

    In this paper we present World Lines as a novel interactive visualization that provides complete control over multiple heterogeneous simulation runs. In many application areas decisions can only be made by exploring alternative scenarios. The goal of the suggested approach is to support users in this decision making process. In this setting the data domain is extended to a set of alternative worlds where only one outcome will actually happen. World Lines integrate simulation visualization and...

  12. Radiation flux measuring device

    Corte, E.; Maitra, P.

    1977-01-01

    A radiation flux measuring device is described which employs a differential pair of transistors, the output of which is maintained constant, connected to a radiation detector. Means connected to the differential pair produce a signal representing the log of the a-c component of the radiation detector, thereby providing a signal representing the true root mean square logarithmic output. 3 claims, 2 figures

  13. Soluble organic nutrient fluxes

    Robert G. Qualls; Bruce L. Haines; Wayne Swank

    2014-01-01

    Our objectives in this study were (i) compare fluxes of the dissolved organic nutrients dissolved organic carbon (DOC), DON, and dissolved organic phosphorus (DOP) in a clearcut area and an adjacent mature reference area. (ii) determine whether concentrations of dissolved organic nutrients or inorganic nutrients were greater in clearcut areas than in reference areas,...

  14. Flux vacua and supermanifolds

    Grassi, Pietro Antonio [CERN, Theory Unit, CH-1211 Geneva, 23 (Switzerland); Marescotti, Matteo [Dipartimento di Fisica Teorica, Universita di Torino, Via Giuria 1, I-10125, Turin (Italy)

    2007-01-15

    As been recently pointed out, physically relevant models derived from string theory require the presence of non-vanishing form fluxes besides the usual geometrical constraints. In the case of NS-NS fluxes, the Generalized Complex Geometry encodes these informations in a beautiful geometrical structure. On the other hand, the R-R fluxes call for supergeometry as the underlying mathematical framework. In this context, we analyze the possibility of constructing interesting supermanifolds recasting the geometrical data and RR fluxes. To characterize these supermanifolds we have been guided by the fact topological strings on supermanifolds require the super-Ricci flatness of the target space. This can be achieved by adding to a given bosonic manifold enough anticommuting coordinates and new constraints on the bosonic sub-manifold. We study these constraints at the linear and non-linear level for a pure geometrical setting and in the presence of p-form field strengths. We find that certain spaces admit several super-extensions and we give a parameterization in a simple case of d bosonic coordinates and two fermionic coordinates. In addition, we comment on the role of the RR field in the construction of the super-metric. We give several examples based on supergroup manifolds and coset supermanifolds.

  15. Flux vacua and supermanifolds

    Grassi, Pietro Antonio; Marescotti, Matteo

    2007-01-01

    As been recently pointed out, physically relevant models derived from string theory require the presence of non-vanishing form fluxes besides the usual geometrical constraints. In the case of NS-NS fluxes, the Generalized Complex Geometry encodes these informations in a beautiful geometrical structure. On the other hand, the R-R fluxes call for supergeometry as the underlying mathematical framework. In this context, we analyze the possibility of constructing interesting supermanifolds recasting the geometrical data and RR fluxes. To characterize these supermanifolds we have been guided by the fact topological strings on supermanifolds require the super-Ricci flatness of the target space. This can be achieved by adding to a given bosonic manifold enough anticommuting coordinates and new constraints on the bosonic sub-manifold. We study these constraints at the linear and non-linear level for a pure geometrical setting and in the presence of p-form field strengths. We find that certain spaces admit several super-extensions and we give a parameterization in a simple case of d bosonic coordinates and two fermionic coordinates. In addition, we comment on the role of the RR field in the construction of the super-metric. We give several examples based on supergroup manifolds and coset supermanifolds

  16. Atmospheric neutrino fluxes

    Perkins, D.H.

    1984-01-01

    The atmospheric neutrino fluxes, which are responsible for the main background in proton decay experiments, have been calculated by two independent methods. There are discrepancies between the two sets of results regarding latitude effects and up-down asymmetries, especially for neutrino energies Esub(ν) < 1 GeV. (author)

  17. Flux scaling: Ultimate regime

    First page Back Continue Last page Overview Graphics. Flux scaling: Ultimate regime. With the Nusselt number and the mixing length scales, we get the Nusselt number and Reynolds number (w'd/ν) scalings: and or. and. scaling expected to occur at extremely high Ra Rayleigh-Benard convection. Get the ultimate regime ...

  18. Weak point disorder in strongly fluctuating flux-line liquids

    of intense research activity in the past fifteen odd years [1–5]. Potential ... types of disorder give rise to a variety of phases, thus making vortex matter an ... A powerful method for describing both clean and ..... We have predicted qualitative.

  19. Flux line lattice symmetries in the borocarbide superconductor ...

    FLL) obtained in the borocarbide superconductor LuNi2B2C with the applied field along the c- and a- axes. For Hc the temperature dependence of the FLL structural phase transition from square to hexagonal symmetry was investigated.

  20. Magnetic relaxation, flux pinning and critical currents in superconductors

    Lichtenberger, K.S.

    1991-01-01

    A systematic study of the magnetic flux pinning properties in superconductors has been undertaken in an attempt to understand the differences between the flux creep behavior of classical superconductors and high-temperature superconductors (HTSC's). In HTSC's, the ratio of the effective flux pinning energy to the thermal energy, U 0 /kT, is much smaller than that of conventional superconductors, often approaching unity. This results in much larger creep rates in HTSC's than in conventional superconductors. It is necessary to find suitable models that describe flux creep in both classical superconductors and HTSC's. Results show that while these two classes of materials are quantitatively very different, a single pinning barrier mode adequately describes both, within the proper region of the H-T plane. The model is applied to a variety of superconductors and the results are contrasted. Although the H-T plane appears to be very different HTSC's than for conventional superconductors, qualitatively the same physics describes both. In HTSC's, near the upper critical field there exists a relatively wide region of superconducting fluctuations, followed successively by regions of thermodynamic reversibility, thermally assisted flux, flux creep, and finally rigid flux lattice where little, if any, motion of the flux lattice occurs. All of these regions are also present in conventional superconductors, but often much more difficult, especially the irreversibility transition and the fluctuation region. The central finding of the flux creep analysis is that the region of flux creep is defined as a band in the H-T plane in which 2 ≤ U 0 /kT ≤ 100, and that the flux creep model applies best within this band

  1. Upper limits on the total cosmic-ray luminosity of individual sources

    Anjos, R.C.; De Souza, V. [Instituto de Física de São Carlos, Universidade de São Paulo, São Paulo (Brazil); Supanitsky, A.D., E-mail: rita@ifsc.usp.br, E-mail: vitor@ifsc.usp.br, E-mail: supanitsky@iafe.uba.ar [Instituto de Astronomía y Física del Espacio (IAFE), CONICET-UBA, Buenos Aires (Argentina)

    2014-07-01

    In this paper, upper limits on the total luminosity of ultra-high-energy cosmic-rays (UHECR) E > 10{sup 18} eV) are determined for five individual sources. The upper limit on the integral flux of GeV--TeV gamma-rays is used to extract the upper limit on the total UHECR luminosity of individual sources. The correlation between upper limit on the integral GeV--TeV gamma-ray flux and upper limit on the UHECR luminosity is established through the cascading process that takes place during propagation of the cosmic rays in the background radiation fields, as explained in reference [1]. Twenty-eight sources measured by FERMI-LAT, VERITAS and MAGIC observatories have been studied. The measured upper limit on the GeV--TeV gamma-ray flux is restrictive enough to allow the calculation of an upper limit on the total UHECR cosmic-ray luminosity of five sources. The upper limit on the UHECR cosmic-ray luminosity of these sources is shown for several assumptions on the emission mechanism. For all studied sources an upper limit on the ultra-high-energy proton luminosity is also set.

  2. Upper limits on the total cosmic-ray luminosity of individual sources

    Anjos, R.C.; De Souza, V.; Supanitsky, A.D.

    2014-01-01

    In this paper, upper limits on the total luminosity of ultra-high-energy cosmic-rays (UHECR) E > 10 18 eV) are determined for five individual sources. The upper limit on the integral flux of GeV--TeV gamma-rays is used to extract the upper limit on the total UHECR luminosity of individual sources. The correlation between upper limit on the integral GeV--TeV gamma-ray flux and upper limit on the UHECR luminosity is established through the cascading process that takes place during propagation of the cosmic rays in the background radiation fields, as explained in reference [1]. Twenty-eight sources measured by FERMI-LAT, VERITAS and MAGIC observatories have been studied. The measured upper limit on the GeV--TeV gamma-ray flux is restrictive enough to allow the calculation of an upper limit on the total UHECR cosmic-ray luminosity of five sources. The upper limit on the UHECR cosmic-ray luminosity of these sources is shown for several assumptions on the emission mechanism. For all studied sources an upper limit on the ultra-high-energy proton luminosity is also set

  3. Indication of the Hanle Effect by Comparing the Scattering Polarization Observed by CLASP in the Ly α and Si iii 120.65 nm Lines

    Ishikawa, R.; Kubo, M.; Kano, R.; Narukage, N.; Bando, T.; Katsukawa, Y.; Giono, G.; Suematsu, Y.; Hara, H. [National Astronomical Observatory of Japan, National Institutes of Natural Science, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Bueno, J. Trujillo [Instituto de Astrofísica de Canarias, E-38205 La Laguna, Tenerife (Spain); Uitenbroek, H. [National Solar Observatory, 3665 Discovery Drive, Boulder, CO 80303 (United States); Tsuneta, S.; Ishikawa, S.; Shimizu, T.; Sakao, T. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo, Sagamihara, Kanagawa 252-5210 (Japan); Goto, M. [National Institute for Fusion Science, National Institutes of Natural Sciences, Toki, Gifu 509-5292 (Japan); Winebarger, A.; Kobayashi, K. [NASA Marshall Space Flight Center, ZP 13, Huntsville, AL 35812 (United States); Cirtain, J. [University of Virginia, Department of Astronomy, 530 McCormick Road, Charlottesville, VA 22904 (United States); Champey, P. [University of Alabama in Huntsville, 301 Sparkman Drive, Huntsville, AL 35899 (United States); and others

    2017-05-20

    The Chromospheric Lyman-Alpha Spectro-Polarimeter is a sounding rocket experiment that has provided the first successful measurement of the linear polarization produced by scattering processes in the hydrogen Ly α line (121.57 nm) radiation of the solar disk. In this paper, we report that the Si iii line at 120.65 nm also shows scattering polarization and we compare the scattering polarization signals observed in the Ly α and Si iii lines in order to search for observational signatures of the Hanle effect. We focus on four selected bright structures and investigate how the U / I spatial variations vary between the Ly α wing, the Ly α core, and the Si iii line as a function of the total unsigned photospheric magnetic flux estimated from Solar Dynamics Observatory /Helioseismic and Magnetic Imager observations. In an internetwork region, the Ly α core shows an antisymmetric spatial variation across the selected bright structure, but it does not show it in other more magnetized regions. In the Si iii line, the spatial variation of U / I deviates from the above-mentioned antisymmetric shape as the total unsigned photospheric magnetic flux increases. A plausible explanation of this difference is the operation of the Hanle effect. We argue that diagnostic techniques based on the scattering polarization observed simultaneously in two spectral lines with very different sensitivities to the Hanle effect, like Ly α and Si iii, are of great potential interest for exploring the magnetism of the upper solar chromosphere and transition region.

  4. Are Polar Field Magnetic Flux Concentrations Responsible for Missing Interplanetary Flux?

    Linker, Jon A.; Downs, C.; Mikic, Z.; Riley, P.; Henney, C. J.; Arge, C. N.

    2012-05-01

    Magnetohydrodynamic (MHD) simulations are now routinely used to produce models of the solar corona and inner heliosphere for specific time periods. These models typically use magnetic maps of the photospheric magnetic field built up over a solar rotation, available from a number of ground-based and space-based solar observatories. The line-of-sight field at the Sun's poles is poorly observed, and the polar fields in these maps are filled with a variety of interpolation/extrapolation techniques. These models have been found to frequently underestimate the interplanetary magnetic flux (Riley et al., 2012, in press, Stevens et al., 2012, in press) near the minimum part of the cycle unless mitigating correction factors are applied. Hinode SOT observations indicate that strong concentrations of magnetic flux may be present at the poles (Tsuneta et al. 2008). The ADAPT flux evolution model (Arge et al. 2010) also predicts the appearance of such concentrations. In this paper, we explore the possibility that these flux concentrations may account for a significant amount of magnetic flux and alleviate discrepancies in interplanetary magnetic flux predictions. Research supported by AFOSR, NASA, and NSF.

  5. Calibration of Ocean Forcing with satellite Flux Estimates (COFFEE)

    Barron, Charlie; Jan, Dastugue; Jackie, May; Rowley, Clark; Smith, Scott; Spence, Peter; Gremes-Cordero, Silvia

    2016-04-01

    Predicting the evolution of ocean temperature in regional ocean models depends on estimates of surface heat fluxes and upper-ocean processes over the forecast period. Within the COFFEE project (Calibration of Ocean Forcing with satellite Flux Estimates, real-time satellite observations are used to estimate shortwave, longwave, sensible, and latent air-sea heat flux corrections to a background estimate from the prior day's regional or global model forecast. These satellite-corrected fluxes are used to prepare a corrected ocean hindcast and to estimate flux error covariances to project the heat flux corrections for a 3-5 day forecast. In this way, satellite remote sensing is applied to not only inform the initial ocean state but also to mitigate errors in surface heat flux and model representations affecting the distribution of heat in the upper ocean. While traditional assimilation of sea surface temperature (SST) observations re-centers ocean models at the start of each forecast cycle, COFFEE endeavors to appropriately partition and reduce among various surface heat flux and ocean dynamics sources. A suite of experiments in the southern California Current demonstrates a range of COFFEE capabilities, showing the impact on forecast error relative to a baseline three-dimensional variational (3DVAR) assimilation using operational global or regional atmospheric forcing. Experiment cases combine different levels of flux calibration with assimilation alternatives. The cases use the original fluxes, apply full satellite corrections during the forecast period, or extend hindcast corrections into the forecast period. Assimilation is either baseline 3DVAR or standard strong-constraint 4DVAR, with work proceeding to add a 4DVAR expanded to include a weak constraint treatment of the surface flux errors. Covariance of flux errors is estimated from the recent time series of forecast and calibrated flux terms. While the California Current examples are shown, the approach is

  6. Flux motion and dissipation in high temperature superconductors

    Tinkham, M.

    1991-01-01

    Two quite different motivations spark the study of flux motion and resistance in the new high-temperature superconductors. Achievement of usefully low resistance at usefully large current densities is the key to most practical applications, but conceptual understanding of the idealized resistive behavior in the O current limit motivates much theoretical work. Some analyses emphasize the pinning of individual flux lines to inhomogeneities in the underlying material; others emphasize the collective aspects of the interacting flux lines, whether liquid, solid, crystalline, or glassy; still others emphasize the concept of percolative Josephson coupling between grains. In this paper an overview is given of these various approaches, their interrelation, and the experiment evidence, including some new results on flux motion in large SNS arrays, treated as a model system

  7. Radial Profile of the 3.5 kev Line Out to R200 in the Perseus Cluster

    Franse, Jeroen; Bulbul, Esra; Foster, Adam; Boyarsky, Alexey; Markevitch, Maxim; Bautz, Mark; Lakubovskyi, Dmytro; Loewenstein, Michael; McDonald, Michael; Miller, Eric; hide

    2016-01-01

    The recent discovery of the unidentified emission line at 3.5 keV in galaxies and clusters has attracted great interest from the community. As the origin of the line remains uncertain, we study the surface brightness distribution of the line in the Perseus cluster since that information can be used to identify its origin. We examine the flux distribution of the 3.5 keV line in the deep Suzaku observations of the Perseus cluster in detail. The 3.5 keV line is observed in three concentric annuli in the central observations, although the observations of the outskirts of the cluster did not reveal such a signal. We establish that these detections and the upper limits from the non-detections are consistent with a dark matter decay origin. However, absence of positive detection in the outskirts is also consistent with some unknown astrophysical origin of the line in the dense gas of the Perseus core, as well as with a dark matter origin with a steeper dependence on mass than the dark matter decay. We also comment on several recently published analyses of the 3.5 keV line.

  8. RADIAL PROFILE OF THE 3.5 keV LINE OUT TO R {sub 200} IN THE PERSEUS CLUSTER

    Franse, Jeroen [Leiden Observatory, Leiden University, Niels Bohrweg 2, Leiden (Netherlands); Bulbul, Esra; Bautz, Mark; McDonald, Michael; Miller, Eric [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Foster, Adam; Randall, Scott W.; Smith, Randall K. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Boyarsky, Alexey [Instituut-Lorentz for Theoretical Physics, Leiden University, Niels Bohrweg 2, Leiden (Netherlands); Markevitch, Maxim [NASA Goddard Space Flight Center, 880 Greenbelt Road, MD 20771 (United States); Iakubovskyi, Dmytro; Ruchayskiy, Oleg [Discovery Center, Niels Bohr Institute, Blegdamsvej 17, Copenhagen (Denmark); Loewenstein, Mike [CRESST and X-ray Astrophysics Laboratory NASA/GSFC, Greenbelt, MD 20771 (United States)

    2016-10-01

    The recent discovery of the unidentified emission line at 3.5 keV in galaxies and clusters has attracted great interest from the community. As the origin of the line remains uncertain, we study the surface brightness distribution of the line in the Perseus cluster since that information can be used to identify its origin. We examine the flux distribution of the 3.5 keV line in the deep Suzaku observations of the Perseus cluster in detail. The 3.5 keV line is observed in three concentric annuli in the central observations, although the observations of the outskirts of the cluster did not reveal such a signal. We establish that these detections and the upper limits from the non-detections are consistent with a dark matter decay origin. However, absence of positive detection in the outskirts is also consistent with some unknown astrophysical origin of the line in the dense gas of the Perseus core, as well as with a dark matter origin with a steeper dependence on mass than the dark matter decay. We also comment on several recently published analyses of the 3.5 keV line.

  9. A LINK BETWEEN X-RAY EMISSION LINES AND RADIO JETS IN 4U 1630-47?

    Neilsen, Joseph [Department of Astronomy, Boston University, Boston, MA 02215 (United States); Coriat, Mickaël [Department of Astronomy, University of Cape Town, Private Bag X3, Rondebosch 7701 (South Africa); Fender, Rob; Broderick, Jess W. [Department of Physics, Oxford University, Oxford OX1 3RH (United Kingdom); Lee, Julia C. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Ponti, Gabriele [Max Planck Institute fur Extraterrestriche Physik, D-85748 Garching (Germany); Tzioumis, Anastasios K.; Edwards, Philip G., E-mail: neilsenj@bu.edu [CSIRO Astronomy and Space Science, Australia Telescope National Facility, P.O. Box 76, Epping, NSW 1710 (Australia)

    2014-03-20

    Recently, Díaz Trigo et al. reported an XMM-Newton detection of relativistically Doppler-shifted emission lines associated with steep-spectrum radio emission in the stellar-mass black hole candidate 4U 1630-47 during its 2012 outburst. They interpreted these lines as indicative of a baryonic jet launched by the accretion disk. Here we present a search for the same lines earlier in the same outburst using high-resolution X-ray spectra from the Chandra HETGS. While our observations (eight months prior to the XMM-Newton campaign) also coincide with detections of steep spectrum radio emission by the Australia Telescope Compact Array, we find no evidence for any relativistic X-ray emission lines. Indeed, despite ∼5 × brighter radio emission, our Chandra spectra allow us to place an upper limit on the flux in the blueshifted Fe XXVI line that is ≳ 20 × weaker than the line observed by Díaz Trigo et al. We explore several scenarios that could explain our differing results, including variations in the geometry of the jet or a mass-loading process or jet baryon content that evolves with the accretion state of the black hole. We also consider the possibility that the radio emission arises in an interaction between a jet and the nearby interstellar medium, in which case the X-ray emission lines might be unrelated to the radio emission.

  10. RADIAL PROFILE OF THE 3.5 keV LINE OUT TO R 200 IN THE PERSEUS CLUSTER

    Franse, Jeroen; Bulbul, Esra; Bautz, Mark; McDonald, Michael; Miller, Eric; Foster, Adam; Randall, Scott W.; Smith, Randall K.; Boyarsky, Alexey; Markevitch, Maxim; Iakubovskyi, Dmytro; Ruchayskiy, Oleg; Loewenstein, Mike

    2016-01-01

    The recent discovery of the unidentified emission line at 3.5 keV in galaxies and clusters has attracted great interest from the community. As the origin of the line remains uncertain, we study the surface brightness distribution of the line in the Perseus cluster since that information can be used to identify its origin. We examine the flux distribution of the 3.5 keV line in the deep Suzaku observations of the Perseus cluster in detail. The 3.5 keV line is observed in three concentric annuli in the central observations, although the observations of the outskirts of the cluster did not reveal such a signal. We establish that these detections and the upper limits from the non-detections are consistent with a dark matter decay origin. However, absence of positive detection in the outskirts is also consistent with some unknown astrophysical origin of the line in the dense gas of the Perseus core, as well as with a dark matter origin with a steeper dependence on mass than the dark matter decay. We also comment on several recently published analyses of the 3.5 keV line.

  11. A LINK BETWEEN X-RAY EMISSION LINES AND RADIO JETS IN 4U 1630-47?

    Neilsen, Joseph; Coriat, Mickaël; Fender, Rob; Broderick, Jess W.; Lee, Julia C.; Ponti, Gabriele; Tzioumis, Anastasios K.; Edwards, Philip G.

    2014-01-01

    Recently, Díaz Trigo et al. reported an XMM-Newton detection of relativistically Doppler-shifted emission lines associated with steep-spectrum radio emission in the stellar-mass black hole candidate 4U 1630-47 during its 2012 outburst. They interpreted these lines as indicative of a baryonic jet launched by the accretion disk. Here we present a search for the same lines earlier in the same outburst using high-resolution X-ray spectra from the Chandra HETGS. While our observations (eight months prior to the XMM-Newton campaign) also coincide with detections of steep spectrum radio emission by the Australia Telescope Compact Array, we find no evidence for any relativistic X-ray emission lines. Indeed, despite ∼5 × brighter radio emission, our Chandra spectra allow us to place an upper limit on the flux in the blueshifted Fe XXVI line that is ≳ 20 × weaker than the line observed by Díaz Trigo et al. We explore several scenarios that could explain our differing results, including variations in the geometry of the jet or a mass-loading process or jet baryon content that evolves with the accretion state of the black hole. We also consider the possibility that the radio emission arises in an interaction between a jet and the nearby interstellar medium, in which case the X-ray emission lines might be unrelated to the radio emission

  12. Upper urinary tract tumors

    Gandrup, Karen L; Nordling, Jørgen; Balslev, Ingegerd

    2014-01-01

    BACKGROUND: Computed tomography urography (CTU) is used widely in the work-up of patients with symptoms of urinary tract lesions. Preoperative knowledge of whether a tumor is invasive or non-invasive is important for the choice of surgery. So far there are no studies about the distinction...... of invasive and non-invasive tumors in ureter and renal pelvis based on the enhancement measured with Hounsfield Units. PURPOSE: To examine the value of CTU using split-bolus technique to distinguish non-invasive from invasive urothelial carcinomas in the upper urinary tract. MATERIAL AND METHODS: Patients...... obtained at CTU could distinguish between invasive and non-invasive lesions. No patients had a CTU within the last year before the examination that resulted in surgery. CONCLUSION: A split-bolus CTU cannot distinguish between invasive and non-invasive urothelial tumors in the upper urinary tract...

  13. Cool seafloor hydrothermal springs reveal global geochemical fluxes

    Wheat, C. Geoffrey; Fisher, Andrew T.; McManus, James; Hulme, Samuel M.; Orcutt, Beth N.

    2017-10-01

    We present geochemical data from the first samples of spring fluids from Dorado Outcrop, a basaltic edifice on 23 M.y. old seafloor of the Cocos Plate, eastern Pacific Ocean. These samples were collected from the discharge of a cool hydrothermal system (CHS) on a ridge flank, where typical reaction temperatures in the volcanic crust are low (2-20 °C) and fluid residence times are short. Ridge-flank hydrothermal systems extract 25% of Earth's lithospheric heat, with a global discharge rate equivalent to that of Earth's river discharge to the ocean; CHSs comprise a significant fraction of this global flow. Upper crustal temperatures around Dorado Outcrop are ∼15 °C, the calculated residence time is V, U, Mg, phosphate, Si and Li are different. Applying these observed differences to calculated global CHS fluxes results in chemical fluxes for these ions that are ≥15% of riverine fluxes. Fluxes of K and B also may be significant, but better analytical resolution is required to confirm this result. Spring fluids also have ∼50% less dissolved oxygen (DO) than bottom seawater. Calculations of an analytical model suggest that the loss of DO occurs primarily (>80%) within the upper basaltic crust by biotic and/or abiotic consumption. This calculation demonstrates that permeable pathways within the upper crust can support oxic water-rock interactions for millions of years.

  14. Design of a flux buffer based on the flux shuttle

    Gershenson, M.

    1991-01-01

    This paper discusses the design considerations for a flux buffer based on the flux-shuttle concept. Particular attention is given to the issues of flux popping, stability of operation and saturation levels for a large input. Modulation techniques used in order to minimize 1/f noise, in addition to offsets are also analyzed. Advantages over conventional approaches using a SQUID for a flux buffer are discussed. Results of computer simulations are presented

  15. The Discovery of a High-Redshift Quasar without Emission Lines from Sloan Digital Sky Survey Commissioning Data.

    Fan; Strauss; Gunn; Lupton; Carilli; Rupen; Schmidt; Moustakas; Davis; Annis; Bahcall; Brinkmann; Brunner; Csabai; Doi; Fukugita; Heckman; Hennessy; Hindsley; Ivezic; Knapp; Lamb; Munn; Pauls; Pier; Rockosi; Schneider; Szalay; Tucker; York

    1999-12-01

    We report observations of a luminous unresolved object at redshift z=4.62, with a featureless optical spectrum redward of the Lyalpha forest region, discovered from Sloan Digital Sky Survey commissioning data. The redshift is determined by the onset of the Lyalpha forest at lambda approximately 6800 Å and a Lyman limit system at lambda=5120 Å. A strong Lyalpha absorption system with weak metal absorption lines at z=4.58 is also identified in the spectrum. The object has a continuum absolute magnitude of -26.6 at 1450 Å in the rest frame (h0=0.5, q0=0.5) and therefore cannot be an ordinary galaxy. It shows no radio emission (the 3 sigma upper limit of its flux at 6 cm is 60 µJy), indicating a radio-to-optical flux ratio at least as small as that of the radio-weakest BL Lacertae objects known. It is also not linearly polarized to a 3 sigma upper limit of 4% in the observed I band. Therefore, it is either the most distant BL Lac object known to date, with very weak radio emission, or a new type of unbeamed quasar, whose broad emission line region is very weak or absent.

  16. Lip line preference for variant face types.

    Anwar, Nabila; Fida, Mubassar

    2012-06-01

    To determine the effect of altered lip line on attractiveness and to find preferred lip line for vertical face types in both genders. Cross-sectional analytical study. The Aga Khan University Hospital, Karachi, from May to July 2009. Photographs of two selected subjects were altered to produce three face types for the same individual with the aim of keeping the frame of the smile constant. Lip line was then altered for both the subjects as: both dentitions visible, upper incisors visible, upper incisors and 2 mm gum and 4 mm gum visible. The pictures were rated by different professionals for attractiveness. Descriptive statistics for the raters and multiple factor ANOVA was used to find the most attractive lip line. The total number of raters was 100 with the mean age of 30.3 ± 8 years. The alterations in the smile parameters produced statistically significant difference in the attractiveness of faces, whereas the perception difference was found to be insignificant amongst raters of different professions. Preferred lip line was the one showing only the upper incisors in dolico and mesofacial male and female genders whereas 2 mm gum show was preferred in brachyfacial subjects. The variability in lip line showed significant difference in the perceived attractiveness. Preferred lip lines as the one showing only the upper incisors in dolico and mesofacial male and female genders whereas 2 mm gum show was preferred in brachyfacial subjects.

  17. Lobotomy of flux compactifications

    Dibitetto, Giuseppe [Institutionen för fysik och astronomi, University of Uppsala,Box 803, SE-751 08 Uppsala (Sweden); Guarino, Adolfo [Albert Einstein Center for Fundamental Physics, Institute for Theoretical Physics,Bern University, Sidlerstrasse 5, CH-3012 Bern (Switzerland); Roest, Diederik [Centre for Theoretical Physics, University of Groningen,Nijenborgh 4 9747 AG Groningen (Netherlands)

    2014-05-15

    We provide the dictionary between four-dimensional gauged supergravity and type II compactifications on T{sup 6} with metric and gauge fluxes in the absence of supersymmetry breaking sources, such as branes and orientifold planes. Secondly, we prove that there is a unique isotropic compactification allowing for critical points. It corresponds to a type IIA background given by a product of two 3-tori with SO(3) twists and results in a unique theory (gauging) with a non-semisimple gauge algebra. Besides the known four AdS solutions surviving the orientifold projection to N=4 induced by O6-planes, this theory contains a novel AdS solution that requires non-trivial orientifold-odd fluxes, hence being a genuine critical point of the N=8 theory.

  18. Silver linings.

    Bultas, Margaret W; Pohlman, Shawn

    2014-01-01

    The purpose of this interpretive phenomenological study was to gain a better understanding of the experiences of 11 mothers of preschool children with autism spectrum disorder (ASD). Mothers were interviewed three times over a 6 week period. Interviews were analyzed using interpretive methods. This manuscript highlights one particular theme-a positive perspective mothers described as the "silver lining." This "silver lining" represents optimism despite the adversities associated with parenting a child with ASD. A deeper understanding of this side of mothering children with ASD may help health care providers improve rapport, communication, and result in more authentic family centered care. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Self-organized critical behavior in pinned flux lattices

    Pla, O.; Nori, F.

    1991-01-01

    We study the response of pinned fluxed lattices, under small perturbations in the driving force, below and close to the pinning-depinning transition. For driving Lorentz forces below F c (the depinning force at which the whole flux lattice slides), the system has instabilities against small force increases, with a power-law distribution characteristic of self-organized criticality. Specifically, D(d)∼d -1,3 , where d is the displacement of a flux line after a very small force increase. We also study the initial stages of the motion of the lattice once the driving force overcomes the pinning forces

  20. The Role of Kinetic Alfven Waves in Plasma Transport in an Ion-scale Flux Rope

    Tang, B.; Li, W.; Wang, C.; Dai, L.

    2017-12-01

    Magnetic flux ropes, if generated by multiply X-line reconnections, would be born as a crater type one, meaning the plasma density within is relatively high. They will then evolve into typical flux ropes as plasma are transported away along the magnetic field lines [Zhang et al., 2010]. In this study, we report an ion-scale flux rope observed by MMS on November 28, 2016, which is accompanied by strong kinetic Alfven waves (KAW). The related wave parallel electric field can effectively accelerate electrons inside the flux rope by Landau resonance, resulting into a significant decrease of the electron at 90° pitch angle. The change of electron pitch angle distribution would cause the rapid plasma transport along the magnetic field lines, and help the flux rope evolve into a strong magnetic core in a short time. This wave-particle interaction would be a candidate mechanism to explain the rareness of crater flux ropes in reality.

  1. Aspects of six-dimensional flux compactifications

    Dierigl, Markus

    2017-08-15

    In this thesis we investigate various aspects of flux compactifications in six-dimensional quantum field theories. After introducing the internal geometries, i.e. the two-dimensional torus T{sup 2} and one of its orbifolds T{sup 2}/Z{sub 2}, we classify possible gauge backgrounds including continuous and discrete Wilson lines with emphasis on a non-vanishing flux density. An operator analogy with the quantum harmonic oscillator allows for an explicit derivation of the mode functions of charged fields and demonstrates the advantage of our interpretation of discrete Wilson lines in terms of localized fractional gauge fluxes. We then derive a globally supersymmetric action which captures the D-term supersymmetry breaking induced by the internal magnetic field and reproduces the Landau level mass spectrum of the charged four-dimensional degrees of freedom. In this context we show that, even though supersymmetry is broken at the compactification scale, the inclusion of the whole tower of charged states leads to vanishing quantum corrections for the Wilson line effective potential on T{sup 2}. This result is supported by a symmetry breaking argument in which the Wilson line appears as a Goldstone boson. After that, we additionally include gravitational effects within a supergravity effective action of the lightest modes in four dimensions. The dynamics of the moduli fields arising after compactification can be encoded in the setup of N=1 supergravity augmented with anomaly cancellation by the Green-Schwarz mechanism. This leads to a non-trivial transformation behavior for two axion fields under gauge variations in the low-energy effective action. As an application, we discuss an SO(10) x U(1) grand unified theory which uses the multiplicity of fermionic zero modes in the flux background to induce the number of matter generations. Finally, we investigate a novel mechanism for generating de Sitter vacua in N=1 supergravity based on a flux-induced positive definite D

  2. Aspects of six-dimensional flux compactifications

    Dierigl, Markus

    2017-08-01

    In this thesis we investigate various aspects of flux compactifications in six-dimensional quantum field theories. After introducing the internal geometries, i.e. the two-dimensional torus T"2 and one of its orbifolds T"2/Z_2, we classify possible gauge backgrounds including continuous and discrete Wilson lines with emphasis on a non-vanishing flux density. An operator analogy with the quantum harmonic oscillator allows for an explicit derivation of the mode functions of charged fields and demonstrates the advantage of our interpretation of discrete Wilson lines in terms of localized fractional gauge fluxes. We then derive a globally supersymmetric action which captures the D-term supersymmetry breaking induced by the internal magnetic field and reproduces the Landau level mass spectrum of the charged four-dimensional degrees of freedom. In this context we show that, even though supersymmetry is broken at the compactification scale, the inclusion of the whole tower of charged states leads to vanishing quantum corrections for the Wilson line effective potential on T"2. This result is supported by a symmetry breaking argument in which the Wilson line appears as a Goldstone boson. After that, we additionally include gravitational effects within a supergravity effective action of the lightest modes in four dimensions. The dynamics of the moduli fields arising after compactification can be encoded in the setup of N=1 supergravity augmented with anomaly cancellation by the Green-Schwarz mechanism. This leads to a non-trivial transformation behavior for two axion fields under gauge variations in the low-energy effective action. As an application, we discuss an SO(10) x U(1) grand unified theory which uses the multiplicity of fermionic zero modes in the flux background to induce the number of matter generations. Finally, we investigate a novel mechanism for generating de Sitter vacua in N=1 supergravity based on a flux-induced positive definite D-term potential. The

  3. DOWNWARD CATASTROPHE OF SOLAR MAGNETIC FLUX ROPES

    Zhang, Quanhao; Wang, Yuming; Hu, Youqiu; Liu, Rui, E-mail: zhangqh@mail.ustc.edu.cn [CAS Key Laboratory of Geospace Environment, Department of Geophysics and Planetary Sciences, University of Science and Technology of China, Hefei 230026 (China)

    2016-07-10

    2.5-dimensional time-dependent ideal magnetohydrodynamic (MHD) models in Cartesian coordinates were used in previous studies to seek MHD equilibria involving a magnetic flux rope embedded in a bipolar, partially open background field. As demonstrated by these studies, the equilibrium solutions of the system are separated into two branches: the flux rope sticks to the photosphere for solutions at the lower branch but is suspended in the corona for those at the upper branch. Moreover, a solution originally at the lower branch jumps to the upper, as the related control parameter increases and reaches a critical value, and the associated jump is here referred to as an upward catastrophe. The present paper advances these studies in three aspects. First, the magnetic field is changed to be force-free; the system still experiences an upward catastrophe with an increase in each control parameter. Second, under the force-free approximation, there also exists a downward catastrophe, characterized by the jump of a solution from the upper branch to the lower. Both catastrophes are irreversible processes connecting the two branches of equilibrium solutions so as to form a cycle. Finally, the magnetic energy in the numerical domain is calculated. It is found that there exists a magnetic energy release for both catastrophes. The Ampère's force, which vanishes everywhere for force-free fields, appears only during the catastrophes and does positive work, which serves as a major mechanism for the energy release. The implications of the downward catastrophe and its relevance to solar activities are briefly discussed.

  4. DOWNWARD CATASTROPHE OF SOLAR MAGNETIC FLUX ROPES

    Zhang, Quanhao; Wang, Yuming; Hu, Youqiu; Liu, Rui

    2016-01-01

    2.5-dimensional time-dependent ideal magnetohydrodynamic (MHD) models in Cartesian coordinates were used in previous studies to seek MHD equilibria involving a magnetic flux rope embedded in a bipolar, partially open background field. As demonstrated by these studies, the equilibrium solutions of the system are separated into two branches: the flux rope sticks to the photosphere for solutions at the lower branch but is suspended in the corona for those at the upper branch. Moreover, a solution originally at the lower branch jumps to the upper, as the related control parameter increases and reaches a critical value, and the associated jump is here referred to as an upward catastrophe. The present paper advances these studies in three aspects. First, the magnetic field is changed to be force-free; the system still experiences an upward catastrophe with an increase in each control parameter. Second, under the force-free approximation, there also exists a downward catastrophe, characterized by the jump of a solution from the upper branch to the lower. Both catastrophes are irreversible processes connecting the two branches of equilibrium solutions so as to form a cycle. Finally, the magnetic energy in the numerical domain is calculated. It is found that there exists a magnetic energy release for both catastrophes. The Ampère's force, which vanishes everywhere for force-free fields, appears only during the catastrophes and does positive work, which serves as a major mechanism for the energy release. The implications of the downward catastrophe and its relevance to solar activities are briefly discussed.

  5. Landscape analysis of soil methane flux across complex terrain

    Kaiser, Kendra E.; McGlynn, Brian L.; Dore, John E.

    2018-05-01

    Relationships between methane (CH4) fluxes and environmental conditions have been extensively explored in saturated soils, while research has been less prevalent in aerated soils because of the relatively small magnitudes of CH4 fluxes that occur in dry soils. Our study builds on previous carbon cycle research at Tenderfoot Creek Experimental Forest, Montana, to identify how environmental conditions reflected by topographic metrics can be leveraged to estimate watershed scale CH4 fluxes from point scale measurements. Here, we measured soil CH4 concentrations and fluxes across a range of landscape positions (7 riparian, 25 upland), utilizing topographic and seasonal (29 May-12 September) gradients to examine the relationships between environmental variables, hydrologic dynamics, and CH4 emission and uptake. Riparian areas emitted small fluxes of CH4 throughout the study (median: 0.186 µg CH4-C m-2 h-1) and uplands increased in sink strength with dry-down of the watershed (median: -22.9 µg CH4-C m-2 h-1). Locations with volumetric water content (VWC) below 38 % were methane sinks, and uptake increased with decreasing VWC. Above 43 % VWC, net CH4 efflux occurred, and at intermediate VWC net fluxes were near zero. Riparian sites had near-neutral cumulative seasonal flux, and cumulative uptake of CH4 in the uplands was significantly related to topographic indices. These relationships were used to model the net seasonal CH4 flux of the upper Stringer Creek watershed (-1.75 kg CH4-C ha-1). This spatially distributed estimate was 111 % larger than that obtained by simply extrapolating the mean CH4 flux to the entire watershed area. Our results highlight the importance of quantifying the space-time variability of net CH4 fluxes as predicted by the frequency distribution of landscape positions when assessing watershed scale greenhouse gas balances.

  6. Physics of magnetic flux ropes

    Russell, C. T.; Priest, E. R.; Lee, L. C.

    The present work encompasses papers on the structure, waves, and instabilities of magnetic flux ropes (MFRs), photospheric flux tubes (PFTs), the structure and heating of coronal loops, solar prominences, coronal mass ejections and magnetic clouds, flux ropes in planetary ionospheres, the magnetopause, magnetospheric field-aligned currents and flux tubes, and the magnetotail. Attention is given to the equilibrium of MFRs, resistive instability, magnetic reconnection and turbulence in current sheets, dynamical effects and energy transport in intense flux tubes, waves in solar PFTs, twisted flux ropes in the solar corona, an electrodynamical model of solar flares, filament cooling and condensation in a sheared magnetic field, the magnetopause, the generation of twisted MFRs during magnetic reconnection, ionospheric flux ropes above the South Pole, substorms and MFR structures, evidence for flux ropes in the earth magnetotail, and MFRs in 3D MHD simulations.

  7. Seasonal and latitudinal variations of surface fluxes at two Arctic terrestrial sites

    Grachev, Andrey A.; Persson, P. Ola G.; Uttal, Taneil; Akish, Elena A.; Cox, Christopher J.; Morris, Sara M.; Fairall, Christopher W.; Stone, Robert S.; Lesins, Glen; Makshtas, Alexander P.; Repina, Irina A.

    2017-11-01

    This observational study compares seasonal variations of surface fluxes (turbulent, radiative, and soil heat) and other ancillary atmospheric/surface/permafrost data based on in-situ measurements made at terrestrial research observatories located near the coast of the Arctic Ocean. Hourly-averaged multiyear data sets collected at Eureka (Nunavut, Canada) and Tiksi (East Siberia, Russia) are analyzed in more detail to elucidate similarities and differences in the seasonal cycles at these two Arctic stations, which are situated at significantly different latitudes (80.0°N and 71.6°N, respectively). While significant gross similarities exist in the annual cycles of various meteorological parameters and fluxes, the differences in latitude, local topography, cloud cover, snowfall, and soil characteristics produce noticeable differences in fluxes and in the structures of the atmospheric boundary layer and upper soil temperature profiles. An important factor is that even though higher latitude sites (in this case Eureka) generally receive less annual incoming solar radiation but more total daily incoming solar radiation throughout the summer months than lower latitude sites (in this case Tiksi). This leads to a counter-intuitive state where the average active layer (or thaw line) is deeper and the topsoil temperature in midsummer are higher in Eureka which is located almost 10° north of Tiksi. The study further highlights the differences in the seasonal and latitudinal variations of the incoming shortwave and net radiation as well as the moderating cloudiness effects that lead to temporal and spatial differences in the structure of the atmospheric boundary layer and the uppermost ground layer. Specifically the warm season (Arctic summer) is shorter and mid-summer amplitude of the surface fluxes near solar noon is generally less in Eureka than in Tiksi. During the dark Polar night and cold seasons (Arctic winter) when the ground is covered with snow and air temperatures

  8. Correction of UBV Photometry for Emission Lines

    Skopal A.

    2003-12-01

    Full Text Available We investigate the effect on U,B,V magnitudes of the removal of emission lines from the spectra of some symbiotic stars and novae during their nebular phases. We approach this problem by the precise reconstruction of the composite UV/optical continuum and the line spectrum. The corrections ΔU, ΔB and ΔV are determined from the ratio of fluxes with and without emission lines. We demonstrate the effect for symbiotic nova V1016 Cyg during its nebular phase. We find that about 68%, 78% and 66% of the observed flux in the U, B and V filters is radiated in the emission lines. The effect should be taken into account before using the observed color indices of emission-line objects for diagnosis of their radiation in the continuum.

  9. in upper gastrointestinal endoscopy

    Sinan Uzman

    2016-07-01

    Full Text Available Introduction : There is increasing interest in sedation for upper gastrointestinal endoscopy (UGE. Prospective randomized studies comparing sedation properties and complications of propofol and midazolam/meperidine in upper gastrointestinal endoscopy (UGE are few. Aim: To compare propofol and midazolam/meperidine sedation for UGE in terms of cardiopulmonary side effects, patient and endoscopist satisfaction and procedure-related times. Material and methods: This was a prospective, randomized, double-blind study of propofol versus midazolam and meperidine in 100 patients scheduled for diagnostic upper gastrointestinal endoscopy. The patients were divided into propofol and midazolam/meperidine groups. Randomization was generated by a computer. Cardiopulmonary side effects (hypotension, bradycardia, hypoxemia, procedure-related times (endoscopy time, awake time, time to hospital discharge, and patient and endoscopist satisfaction were compared between groups. Results: There was no significant difference between the groups with respect to the cost, endoscopy time, or demographic and clinical characteristics of the patients. Awake time and time to hospital discharge were significantly shorter in the propofol group (6.58 ±4.72 vs. 9.32 ±4.26 min, p = 0.030 and 27.60 ±7.88 vs. 32.00 ±10.54 min, p = 0.019. Hypotension incidence was significantly higher in the propofol group (12% vs. 0%, p = 0.027. The patient and endoscopist satisfaction was better with propofol. Conclusions : Propofol may be preferred to midazolam/meperidine sedation, with a shorter awake and hospital discharge time and better patient and endoscopist satisfaction. However, hypotension risk should be considered with propofol, and careful evaluation is needed, particularly in cardiopulmonary disorders.

  10. Upper extremity golf injuries.

    Cohn, Michael A; Lee, Steven K; Strauss, Eric J

    2013-01-01

    Golf is a global sport enjoyed by an estimated 60 million people around the world. Despite the common misconception that the risk of injury during the play of golf is minimal, golfers are subject to a myriad of potential pathologies. While the majority of injuries in golf are attributable to overuse, acute traumatic injuries can also occur. As the body's direct link to the golf club, the upper extremities are especially prone to injury. A thorough appreciation of the risk factors and patterns of injury will afford accurate diagnosis, treatment, and prevention of further injury.

  11. Reconstruction of vacuum magnetic flux in QUEST

    Ishiguro, Masaki; Hanada, Kazuaki; Nakamura, Kazuo

    2010-01-01

    It is important to determine the best method for reconstructing the magnetic flux when eddy currents are significantly induced during magnetic measurement in spherical tokamaks (STs). Four methods for this reconstruction are investigated, and the calculated magnetic fluxes are compared to those measured in the cavity of a vacuum vessel. The results show that the best method is the one that uses currents from virtual coils for reconstruction. In this method, the placement of the virtual coils is optimized with numerical simulations using the Akaike information criterion (AIC), which indicates the goodness of fit of models used to fit measured data. The virtual coils are set on a line 15 cm outside the vacuum vessel. (author)

  12. Formation and evolution of plasmoids and flux-ropes in the Earth's Magnetotail

    Ge, Y.; Raeder, J.

    2013-12-01

    The observation of plasmoids and flux-ropes in the Earth's magnetotail was crucial to establish the simultaneous presence of multiple x-lines in the tail, and has become the basis for the Near Earth Neutral Line (NENL) model of substorms. While the 'classical' NENL model envisions x-lines that extend across the entire tail, recent observations have shown that neither do the x-lines and resulting plasmoids encompass the entire tail, nor do the x-lines have to lie along the y-axis. Furthermore, several x-line/plasmoid/flux-rope structures can exist simultaneously. The fragmentation of the tail by spatially and temporally limited x-lines has important consequences for the mass and energy budget of the tail. Recent ARTEMIS observations have shown that the plasmoids in the distant tail are limited in the Y direction and some flux ropes are tilted during their tailward propagation. In this study we simulate plasmoids and flux-ropes in the Earth's magnetotail using the Open Global Geospace Circulation Model (OpenGGCM). We investigate the generation mechanisms for tail plasmoids and flux-ropes and their evolution as they propagate in the magnetotail. The simulation results show that the limited extend of NENL controls the length or the Y scale of tail plasmoid and flux rope. In addition, by studying their 3D magnetic topology we find that tilted flux ropes form due to a progressive spreading of the reconnection line along the east-west direction, which produces and releases the two ends of the flux rope at different times and at different speeds. By constructing a catalogue of observational signatures of plasmoid and flux rope we compare the differences of their signatures and find that large-scale plasmoids have much weaker core fields than that found inside the small-scale flux ropes.

  13. Upper Grades Ideas.

    Thornburg, David; Beane, Pam

    1983-01-01

    Presents programming ideas using LOGO, activity for converting flowchart into a computer program, and a Pascal program for generating music using paddles. Includes the article "Helping Computers Adapt to Kids" by Philip Nothnagle; a program for estimating length of lines is included. (JN)

  14. Australian methane fluxes

    Williams, D.J.

    1990-01-01

    Estimates are provided for the amount of methane emitted annually into the atmosphere in Australia for a variety of sources. The sources considered are coal mining, landfill, motor vehicles, natural gas suply system, rice paddies, bushfires, termites, wetland and animals. This assessment indicates that the major sources of methane are natural or agricultural in nature and therefore offer little scope for reduction. Nevertheless the remainder are not trival and reduction of these fluxes could play a significant part in any Australian action on the greenhouse problem. 19 refs., 7 tabs., 1 fig

  15. Critical heat flux evaluation

    Banner, D.

    1995-01-01

    Critical heat flux (CHF) is of importance for nuclear safety and represents the major limiting factors for reactor cores. Critical heat flux is caused by a sharp reduction in the heat transfer coefficient located at the outer surface of fuel rods. Safety requires that this phenomenon also called the boiling crisis should be precluded under nominal or incidental conditions (Class I and II events). CHF evaluation in reactor cores is basically a two-step approach. Fuel assemblies are first tested in experimental loops in order to determine CHF limits under various flow conditions. Then, core thermal-hydraulic calculations are performed for safety evaluation. The paper will go into more details about the boiling crisis in order to pinpoint complexity and lack of fundamental understanding in many areas. Experimental test sections needed to collect data over wide thermal-hydraulic and geometric ranges are described CHF safety margin evaluation in reactors cores is discussed by presenting how uncertainties are mentioned. From basic considerations to current concerns, the following topics are discussed; knowledge of the boiling crisis, CHF predictors, and advances thermal-hydraulic codes. (authors). 15 refs., 4 figs

  16. Neutron flux monitor

    Seki, Eiji; Tai, Ichiro.

    1984-01-01

    Purpose: To maintain the measuring accuracy and the reponse time within an allowable range in accordance with the change of neutron fluxes in a nuclear reactor pressure vessel. Constitution: Neutron fluxes within a nuclear reactor pressure vessel are detected by detectors, converted into pulse signals and amplified in a range switching amplifier. The amplified signals are further converted through an A/D converter and digital signals from the converter are subjected to a square operation in an square operation circuit. The output from the circuit is inputted into an integration circuit to selectively accumulate the constant of 1/2n, 1 - 1/2n (n is a positive integer) respectively for two continuing signals to perform weighing. Then, the addition is carried out to calculate the integrated value and the addition number is changed by the chane in the number n to vary the integrating time. The integrated value is inputted into a control circuit to control the value of n so that the fluctuation and the calculation time for the integrated value are within a predetermined range and, at the same time, the gain of the range switching amplifier is controlled. (Seki, T.)

  17. Flux pinning by voids in surface-oxidized superconducting niobium and vanadium

    Meij, G.P. van der.

    1984-03-01

    The volume pinning force in several niobium and vanadium samples with voids is determined at various temperatures. Reasonable agreement is found with the collective pinning theory of Larkin and Ovchinnikov above the field of maximum pinning, if the flux line lattice is assumed to be amorphous in this region and if the elementary pinning force is calculated from the quasi-classical theory of Thuneberg, Kurkijaervi, and Rainer. Also some history and relaxation effects are studied in an alternating field. A qualitative explanation is given in terms of flux line dislocations, which reduce the shear strength of the flux line lattice. (Auth.)

  18. Satellite-based Calibration of Heat Flux at the Ocean Surface

    Barron, C. N.; Dastugue, J. M.; May, J. C.; Rowley, C. D.; Smith, S. R.; Spence, P. L.; Gremes-Cordero, S.

    2016-02-01

    Model forecasts of upper ocean heat content and variability on diurnal to daily scales are highly dependent on estimates of heat flux through the air-sea interface. Satellite remote sensing is applied to not only inform the initial ocean state but also to mitigate errors in surface heat flux and model representations affecting the distribution of heat in the upper ocean. Traditional assimilation of sea surface temperature (SST) observations re-centers ocean models at the start of each forecast cycle. Subsequent evolution depends on estimates of surface heat fluxes and upper-ocean processes over the forecast period. The COFFEE project (Calibration of Ocean Forcing with satellite Flux Estimates) endeavors to correct ocean forecast bias through a responsive error partition among surface heat flux and ocean dynamics sources. A suite of experiments in the southern California Current demonstrates a range of COFFEE capabilities, showing the impact on forecast error relative to a baseline three-dimensional variational (3DVAR) assimilation using Navy operational global or regional atmospheric forcing. COFFEE addresses satellite-calibration of surface fluxes to estimate surface error covariances and links these to the ocean interior. Experiment cases combine different levels of flux calibration with different assimilation alternatives. The cases may use the original fluxes, apply full satellite corrections during the forecast period, or extend hindcast corrections into the forecast period. Assimilation is either baseline 3DVAR or standard strong-constraint 4DVAR, with work proceeding to add a 4DVAR expanded to include a weak constraint treatment of the surface flux errors. Covariance of flux errors is estimated from the recent time series of forecast and calibrated flux terms. While the California Current examples are shown, the approach is equally applicable to other regions. These approaches within a 3DVAR application are anticipated to be useful for global and larger

  19. Oriental upper blepharoplasty.

    Weng, Chau-Jin

    2009-02-01

    Aesthetic surgery of the upper eyelids is a very common procedure performed in cosmetic practices around the world. The word blepharoplasty, however, has a different meaning in Asia than it does elsewhere. Orientals have different periorbital anatomic characteristics, their motivations for seeking eyelid treatment are different, and operative techniques have been adapted consequently. There are also many eyelid shapes among Orientals, mostly with regard to the presence and location of the supratarsal fold and/or presence of an epicanthal fold. The surgeon must therefore master a range of surgical procedures to treat these variations adequately. It is critical to know the indications for each blepharoplasty technique as well as their complications to select the right surgery and avoid unfavorable results. Epicanthoplasty performed on the right patient can greatly improve aesthetic results while retaining ethnic characteristics. This article will discuss Oriental eyelid characteristics, preoperative patient assessment, commonly used corrective techniques for the "double-eyelid" creation, and complications and how to avoid them.

  20. Formation and evolution of plasmoid and flux-rope in the Earth's Magnetotail

    Ge, Yasong; Raeder, Joachim

    2015-04-01

    The observation of plasmoids and flux-ropes in the Earth's magnetotail was crucial to establish the simultaneous presence of multiple x-lines in the tail, and has become the basis for the Near Earth Neutral Line (NENL) model of substorms. While the "classical" NENL model envisions x-lines that extend across the entire tail, recent observations have shown that neither do the x-lines and resulting plasmoids encompass the entire tail, nor do the x-lines have to lie along the y-axis. The fragmentation of the tail by spatially and temporally limited x-lines has important consequences for the mass and energy budget of the tail. Recent ARTEMIS observations have shown that the plasmoids in the distant tail are limited in the Y direction and some flux ropes are tilted during their tailward propagation. Understanding their formation and evolution during their propagation through the magnetotail shall shred more light on the general energy and flux transport of the Earth's magnetosphere. In this study we simulate plasmoids and flux-ropes in the Earth's magnetotail using the Open Global Geospace Circulation Model (OpenGGCM). We investigate the generation mechanisms for tail plasmoids and flux-ropes and their evolution as they propagate in the magnetotail. The simulation results show that the limited extend of NENL controls the length or the Y scale of tail plasmoid and flux rope. In addition, by studying their 3D magnetic topology we find that the tilted flux rope forms due to a progressive spreading of reconnection line along the east-west direction, which produces and releases two ends of the flux rope at different times and in different speeds. By constructing a catalogue of observational signatures of plasmoid and flux rope we compare the differences of their signatures and find that large-scale plasmoids have much weaker core fields than that inside the small-scale flux ropes.

  1. Global simulation of formation and evolution of plasmoid and flux-rope in the Earth's Magnetotail

    Ge, Y.; Raeder, J.; Du, A.

    2014-12-01

    The observation of plasmoids and flux-ropes in the Earth's magnetotail was crucial to establish the simultaneous presence of multiple x-lines in the tail, and has become the basis for the Near Earth Neutral Line (NENL) model of substorms. While the "classical" NENL model envisions x-lines that extend across the entire tail, recent observations have shown that neither do the x-lines and resulting plasmoids encompass the entire tail, nor do the x-lines have to lie along the y-axis. The fragmentation of the tail by spatially and temporally limited x-lines has important consequences for the mass and energy budget of the tail. Recent ARTEMIS observations have shown that the plasmoids in the distant tail are limited in the Y direction and some flux ropes are tilted during their tailward propagation. Understanding their formation and evolution during their propagation through the magnetotail shall shred more light on the general energy and flux transport of the Earth's magnetosphere. In this study we simulate plasmoids and flux-ropes in the Earth's magnetotail using the Open Global Geospace Circulation Model (OpenGGCM). We investigate the generation mechanisms for tail plasmoids and flux-ropes and their evolution as they propagate in the magnetotail. The simulation results show that the limited extend of NENL controls the length or the Y scale of tail plasmoid and flux rope. In addition, by studying their 3D magnetic topology we find that the tilted flux rope forms due to a progressive spreading of reconnection line along the east-west direction, which produces and releases two ends of the flux rope at different times and in different speeds. By constructing a catalogue of observational signatures of plasmoid and flux rope we compare the differences of their signatures and find that large-scale plasmoids have much weaker core fields than that inside the small-scale flux ropes.

  2. production lines

    Jingshan Li

    2000-01-01

    Full Text Available In this work, serial production lines with finished goods buffers operating in the pull regime are considered. The machines are assumed to obey Bernoulli reliability model. The problem of satisfying customers demand is addressed. The level of demand satisfaction is quantified by the due-time performance (DTP, which is defined as the probability to ship to the customer a required number of parts during a fixed time interval. Within this scenario, the definitions of DTP bottlenecks are introduced and a method for their identification is developed.

  3. Cosmic ray induced charged particle albedos in the upper atmosphere

    Bhatnagar, S.P.; Verma, S.D.

    1982-01-01

    There are several observations made in balloon and satellite experiments of relativistic albedo electrons in 50 to 10,000 MeV energy region. The spectrum of these electrons is a power law with negative exponent. At lower energies, 1 to 50 MeV region theoretical evaluations indicate that their energy spectrum will have a similar shape, thus the flux at low energies will be much higher. The only spectrum measurements available below 20 MeV were taken at Ft. Churchill by Hovestadt and Meyer (1969). The flux and energy spectrum of the Re-entrant albedos electrons have been calculated in the energy range 3-50 MeV for Ft. Churchill, Canada, Palestein, Texas and Hyderabad, India, and are presented. The angular distribution of re-entrant electrons in the upper atmosphere is not yet observed, however Kurnosova et. al. (1979) have measured the Vertical and Horizontal integral flux at Hyderabad, India

  4. Line facilities outline

    1998-08-01

    This book deals with line facilities. The contents of this book are outline line of wire telecommunication ; development of line, classification of section of line and theory of transmission of line, cable line ; structure of line, line of cable in town, line out of town, domestic cable and other lines, Optical communication ; line of optical cable, transmission method, measurement of optical communication and cable of the sea bottom, Equipment of telecommunication line ; telecommunication line facilities and telecommunication of public works, construction of cable line and maintenance and Regulation of line equipment ; regulation on technique, construction and maintenance.

  5. Mg II Line Variation of 32 Cygni

    Young Woon Kang

    1992-12-01

    Full Text Available The Mg II lines have been extracted from the IUE archival spectra of 32 Cygni to investigate the effect of the atmospheric eclipse. The UV light curve has been reduced from the continuum flux at the center wavelength of 2807.5 Å in the IUE spectra. The equivalent width of the Mg II k absoption line has been measured for each spectra. The results of the light variation and flux tracing of the absorption line at the vicinity of the primary eclipse confirmed the atmospheric eclipse. The atmospheric effect lasted until the phase 0.06 in the absorptin line tracing, while it lasted until the phase 0.02 in the UV light curve, respectively.

  6. Fast Flux Test Facility

    Munn, W.I.

    1981-01-01

    The Fast Flux Test Facility (FFTF), located on the Hanford site a few miles north of Richland, Washington, is a major link in the chain of development required to sustain and advance Liquid Metal Fast Breeder Reactor (LMFBR) technology in the United States. This 400 MWt sodium cooled reactor is a three loop design, is operated by Westinghouse Hanford Company for the US Department of Energy, and is the largest research reactor of its kind in the world. The purpose of the facility is three-fold: (1) to provide a test bed for components, materials, and breeder reactor fuels which can significantly extend resource reserves; (2) to produce a complete body of base data for the use of liquid sodium in heat transfer systens; and (3) to demonstrate inherent safety characteristics of LMFBR designs

  7. Anomaly detection using magnetic flux leakage technology

    Rempel, Raymond G. [BJ Pipeline Inspection Services, Alberta (Canada)

    2005-07-01

    There are many aspects to properly assessing the integrity of a pipeline. In-line-Inspection (ILI) tools, in particular those that employ the advanced use of Magnetic Flux Leakage (MFL) technology, provide a valuable means of achieving required up-to-date knowledge of a pipeline. More prevalent use of High Resolution MFL In-Line-Inspection tools is growing the knowledge base that leads to more reliable and accurate identification of anomalies in a pipeline, thus, minimizing the need for expensive verification excavations. Accurate assessment of pipeline anomalies can improve the decision making process within an Integrity Management Program and excavation programs can then focus on required repairs instead of calibration or exploratory digs. Utilizing the information from an MFL ILI inspection is not only cost effective but, as well, can also prove to be an extremely valuable building block of a Pipeline Integrity Management Program. (author)

  8. Analytic flux formulas and tables of shielding functions

    Wallace, O.J.

    1981-06-01

    Hand calculations of radiation flux and dose rates are often useful in evaluating radiation shielding and in determining the scope of a problem. The flux formulas appropriate to such calculations are almost always based on the point kernel and allow for at most the consideration of laminar slab shields. These formulas often require access to tables of values of integral functions for effective use. Flux formulas and function tables appropriate to calculations involving homogeneous source regions with the shapes of lines, disks, slabs, truncated cones, cylinders, and spheres are presented. Slab shields may be included in most of these calculations, and the effect of a cylindrical shield surrounding a cylindrical source may be estimated. Detector points may be located axially, laterally, or interior to a cylindrical source. Line sources may be tilted with respect to a slab shield. All function tables are given for a wide range of arguments

  9. Flux compactifications and generalized geometries

    Grana, Mariana

    2006-01-01

    Following the lectures given at CERN Winter School 2006, we present a pedagogical overview of flux compactifications and generalized geometries, concentrating on closed string fluxes in type II theories. We start by reviewing the supersymmetric flux configurations with maximally symmetric four-dimensional spaces. We then discuss the no-go theorems (and their evasion) for compactifications with fluxes. We analyse the resulting four-dimensional effective theories for Calabi-Yau and Calabi-Yau orientifold compactifications, concentrating on the flux-induced superpotentials. We discuss the generic mechanism of moduli stabilization and illustrate with two examples: the conifold in IIB and a T 6 /(Z 3 x Z 3 ) torus in IIA. We finish by studying the effective action and flux vacua for generalized geometries in the context of generalized complex geometry

  10. Flux compactifications and generalized geometries

    Grana, Mariana [Service de Physique Theorique, CEA/Saclay, 91191 Gif-sur-Yvette Cedex (France)

    2006-11-07

    Following the lectures given at CERN Winter School 2006, we present a pedagogical overview of flux compactifications and generalized geometries, concentrating on closed string fluxes in type II theories. We start by reviewing the supersymmetric flux configurations with maximally symmetric four-dimensional spaces. We then discuss the no-go theorems (and their evasion) for compactifications with fluxes. We analyse the resulting four-dimensional effective theories for Calabi-Yau and Calabi-Yau orientifold compactifications, concentrating on the flux-induced superpotentials. We discuss the generic mechanism of moduli stabilization and illustrate with two examples: the conifold in IIB and a T{sup 6} /(Z{sub 3} x Z{sub 3}) torus in IIA. We finish by studying the effective action and flux vacua for generalized geometries in the context of generalized complex geometry.

  11. Calving fluxes and basal melt rates of Antarctic ice shelves

    Depoorter, M.A.; Bamber, J.L.; Griggs, J.A.; Lenaerts, J.T.M.; Ligtenberg, S.R.M.; van den Broeke, M.R.; Moholdt, G.

    2013-01-01

    Iceberg calving has been assumed to be the dominant cause of mass loss for the Antarctic ice sheet, with previous estimates of the calving flux exceeding 2,000 gigatonnes per year1, 2. More recently, the importance of melting by the ocean has been demonstrated close to the grounding line and near

  12. Geometrical Relationship Between Interplanetary Flux Ropes and Their Solar Sources

    Marubashi, K.; Akiyama, S.; Yashiro, S.; Gopalswamy, N.; Cho, K.-S.; Park, Y.-D.

    2015-05-01

    We investigated the physical connection between interplanetary flux ropes (IFRs) near Earth and coronal mass ejections (CMEs) by comparing the magnetic field structures of IFRs and CME source regions. The analysis is based on the list of 54 pairs of ICMEs (interplanetary coronal mass ejections) and CMEs that are taken to be the most probable solar source events. We first attempted to identify the flux rope structure in each of the 54 ICMEs by fitting models with a cylinder and torus magnetic field geometry, both with a force-free field structure. This analysis determined the possible geometries of the identified flux ropes. Then we compared the flux rope geometries with the magnetic field structure of the solar source regions. We obtained the following results: (1) Flux rope structures are seen in 51 ICMEs out of the 54. The result implies that all ICMEs have an intrinsic flux rope structure, if the three exceptional cases are attributed to unfavorable observation conditions. (2) It is possible to find flux rope geometries with the main axis orientation close to the orientation of the magnetic polarity inversion line (PIL) in the solar source regions, the differences being less than 25°. (3) The helicity sign of an IFR is strongly controlled by the location of the solar source: flux ropes with positive (negative) helicity are associated with sources in the southern (northern) hemisphere (six exceptions were found). (4) Over two-thirds of the sources in the northern hemisphere are concentrated along PILs with orientations of 45° ± 30° (measured clockwise from the east), and over two-thirds in the southern hemisphere along PILs with orientations of 135° ± 30°, both corresponding to the Hale boundaries. These results strongly support the idea that a flux rope with the main axis parallel to the PIL erupts in a CME and that the erupted flux rope propagates through the interplanetary space with its orientation maintained and is observed as an IFR.

  13. Plasmas fluxes to surfaces for an oblique magnetic field

    Pitcher, C.S.; Stangeby, P.C.; Elder, J.D.; Bell, M.G.; Kilpatrick, S.J.; Manos, D.M.; Medley, S.S.; Owens, D.K.; Ramsey, A.T.; Ulrickson, M.

    1992-07-01

    The poloidal and toroidal spatial distributions of D α , He I and C II emission have been obtained in the vicinity of the TFTR bumper limiter and are compared with models of ion flow to the surface. The distributions are found not to agree with a model (the ''Cosine'' model) which determines the incident flux density using only the parallel fluxes in the scrape-off layer and the projected area of the surface perpendicular to the field lines. In particular, the Cosine model is not able to explain the significant fluxes observed at locations on the surface which are oblique to the magnetic field. It is further shown that these fluxes cannot be explained by the finite Larmor radius of impinging ions. Finally, it is demonstrated, with the use of Monte Carlo codes, that the distributions can be explained by including both parallel and cross-field transport onto the limiter surface

  14. Observation of a commensurate array of flux chains in tilted flux lattices in Bi-Sr-Ca-Cu-O single crystals

    Bolle, C.A.; Gammel, P.L.; Grier, D.G.; Murray, C.A.; Bishop, D.J.; Mitzi, D.B.; Kapitulnik, A.

    1991-01-01

    We report the observation of a novel flux-lattice structure, a commensurate array of flux-line chains. Our experiments consist of the magnetic decoration of the flux lattices in single crystals of Ba-Sr-Ca-Cu-O where the magnetic field is applied at an angle with respect to the conducting planes. For a narrow range of angles, the equilibrium structure is one with uniformly spaced chains with a higher line density of vortices than the background lattice. Our observations are in qualitative agreement with theories which suggest that, in strongly anisotropic materials the vortices develop an attractive interaction in tilted magnetic fields

  15. Higher Incision at Upper Part of Lower Segment Caesarean Section

    Yong Shao

    2014-06-01

    Conclusions: An incision at the upper part of the lower segment reduces blood loss, enhances uterine retraction, predisposes to fewer complications, is easier to repair, precludes bladder adhesion to the suture line and reduces operation time. Keywords: caesarean section; higher incision technique; traditional uterine incision technique.

  16. Parallel Lines

    James G. Worner

    2017-05-01

    Full Text Available James Worner is an Australian-based writer and scholar currently pursuing a PhD at the University of Technology Sydney. His research seeks to expose masculinities lost in the shadow of Australia’s Anzac hegemony while exploring new opportunities for contemporary historiography. He is the recipient of the Doctoral Scholarship in Historical Consciousness at the university’s Australian Centre of Public History and will be hosted by the University of Bologna during 2017 on a doctoral research writing scholarship.   ‘Parallel Lines’ is one of a collection of stories, The Shapes of Us, exploring liminal spaces of modern life: class, gender, sexuality, race, religion and education. It looks at lives, like lines, that do not meet but which travel in proximity, simultaneously attracted and repelled. James’ short stories have been published in various journals and anthologies.

  17. Heat Flux Instrumentation Laboratory (HFIL)

    Federal Laboratory Consortium — Description: The Heat Flux Instrumentation Laboratory is used to develop advanced, flexible, thin film gauge instrumentation for the Air Force Research Laboratory....

  18. Seasonal and diurnal variability of the meteor flux at high latitudes observed using PFISR

    Sparks, J. J.; Janches, D.; Nicolls, M. J.; Heinselman, C. J.

    2009-05-01

    We report in this and a companion paper [Fentzke, J.T., Janches, D., Sparks, J.J., 2008. Latitudinal and seasonal variability of the micrometeor input function: A study using model predictions and observations from Arecibo and PFISR. Journal of Atmospheric and Solar-Terrestrial Physics, this issue, doi:10.1016/j.jastp.2008.07.015] a complete seasonal study of the micrometeor input function (MIF) at high latitudes using meteor head-echo radar observations performed with the Poker Flat Incoherent Scatter Radar (PFISR). This flux is responsible for a number of atmospheric phenomena; for example, it could be the source of meteoric smoke that is thought to act as condensation nuclei in the formation of ice particles in the polar mesosphere. The observations presented here were performed for full 24-h periods near the summer and winter solstices and spring and autumn equinoxes, times at which the seasonal variability of the MIF is predicted to be large at high latitudes [Janches, D., Heinselman, C.J., Chau, J.L., Chandran, A., Woodman, R., 2006. Modeling of the micrometeor input function in the upper atmosphere observed by High Power and Large Aperture Radars, JGR, 11, A07317, doi:10.1029/2006JA011628]. Precise altitude and radar instantaneous line-of-sight (radial) Doppler velocity information are obtained for each of the hundreds of events detected every day. We show that meteor rates, altitude, and radial velocity distributions have a large seasonal dependence. This seasonal variability can be explained by a change in the relative location of the meteoroid sources with respect to the observer. Our results show that the meteor flux into the upper atmosphere is strongly anisotropic and its characteristics must be accounted for when including this flux into models attempting to explain related aeronomical phenomena. In addition, the measured acceleration and received signal strength distribution do not seem to depend on season; which may suggest that these observed

  19. Measurements of EUV coronal holes and open magnetic flux

    Lowder, C.; Qiu, J.; Leamon, R.; Liu, Y.

    2014-01-01

    Coronal holes are regions on the Sun's surface that map the footprints of open magnetic field lines. We have developed an automated routine to detect and track boundaries of long-lived coronal holes using full-disk extreme-ultraviolet (EUV) images obtained by SOHO/EIT, SDO/AIA, and STEREO/EUVI. We measure coronal hole areas and magnetic flux in these holes, and compare the measurements with calculations by the potential field source surface (PFSS) model. It is shown that, from 1996 through 2010, the total area of coronal holes measured with EIT images varies between 5% and 17% of the total solar surface area, and the total unsigned open flux varies between (2-5)× 10 22 Mx. The solar cycle dependence of these measurements is similar to the PFSS results, but the model yields larger hole areas and greater open flux than observed by EIT. The AIA/EUVI measurements from 2010-2013 show coronal hole area coverage of 5%-10% of the total surface area, with significant contribution from low latitudes, which is under-represented by EIT. AIA/EUVI have measured much enhanced open magnetic flux in the range of (2-4)× 10 22 Mx, which is about twice the flux measured by EIT, and matches with the PFSS calculated open flux, with discrepancies in the location and strength of coronal holes. A detailed comparison between the three measurements (by EIT, AIA-EUVI, and PFSS) indicates that coronal holes in low latitudes contribute significantly to the total open magnetic flux. These low-latitude coronal holes are not well measured with either the He I 10830 line in previous studies, or EIT EUV images; neither are they well captured by the static PFSS model. The enhanced observations from AIA/EUVI allow a more accurate measure of these low-latitude coronal holes and their contribution to open magnetic flux.

  20. Measurements of EUV coronal holes and open magnetic flux

    Lowder, C.; Qiu, J.; Leamon, R. [Department of Physics, Montana State University, Bozeman, MT 59717 (United States); Liu, Y., E-mail: clowder@solar.physics.montana.edu [W. W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305 (United States)

    2014-03-10

    Coronal holes are regions on the Sun's surface that map the footprints of open magnetic field lines. We have developed an automated routine to detect and track boundaries of long-lived coronal holes using full-disk extreme-ultraviolet (EUV) images obtained by SOHO/EIT, SDO/AIA, and STEREO/EUVI. We measure coronal hole areas and magnetic flux in these holes, and compare the measurements with calculations by the potential field source surface (PFSS) model. It is shown that, from 1996 through 2010, the total area of coronal holes measured with EIT images varies between 5% and 17% of the total solar surface area, and the total unsigned open flux varies between (2-5)× 10{sup 22} Mx. The solar cycle dependence of these measurements is similar to the PFSS results, but the model yields larger hole areas and greater open flux than observed by EIT. The AIA/EUVI measurements from 2010-2013 show coronal hole area coverage of 5%-10% of the total surface area, with significant contribution from low latitudes, which is under-represented by EIT. AIA/EUVI have measured much enhanced open magnetic flux in the range of (2-4)× 10{sup 22} Mx, which is about twice the flux measured by EIT, and matches with the PFSS calculated open flux, with discrepancies in the location and strength of coronal holes. A detailed comparison between the three measurements (by EIT, AIA-EUVI, and PFSS) indicates that coronal holes in low latitudes contribute significantly to the total open magnetic flux. These low-latitude coronal holes are not well measured with either the He I 10830 line in previous studies, or EIT EUV images; neither are they well captured by the static PFSS model. The enhanced observations from AIA/EUVI allow a more accurate measure of these low-latitude coronal holes and their contribution to open magnetic flux.

  1. KoFlux: Korean Regional Flux Network in AsiaFlux

    Kim, J.

    2002-12-01

    AsiaFlux, the Asian arm of FLUXNET, held the Second International Workshop on Advanced Flux Network and Flux Evaluation in Jeju Island, Korea on 9-11 January 2002. In order to facilitate comprehensive Asia-wide studies of ecosystem fluxes, the meeting launched KoFlux, a new Korean regional network of long-term micrometeorological flux sites. For a successful assessment of carbon exchange between terrestrial ecosystems and the atmosphere, an accurate measurement of surface fluxes of energy and water is one of the prerequisites. During the 7th Global Energy and Water Cycle Experiment (GEWEX) Asian Monsoon Experiment (GAME) held in Nagoya, Japan on 1-2 October 2001, the Implementation Committee of the Coordinated Enhanced Observing Period (CEOP) was established. One of the immediate tasks of CEOP was and is to identify the reference sites to monitor energy and water fluxes over the Asian continent. Subsequently, to advance the regional and global network of these reference sites in the context of both FLUXNET and CEOP, the Korean flux community has re-organized the available resources to establish a new regional network, KoFlux. We have built up domestic network sites (equipped with wind profiler and radiosonde measurements) over deciduous and coniferous forests, urban and rural rice paddies and coastal farmland. As an outreach through collaborations with research groups in Japan, China and Thailand, we also proposed international flux sites at ecologically and climatologically important locations such as a prairie on the Tibetan plateau, tropical forest with mixed and rapid land use change in northern Thailand. Several sites in KoFlux already begun to accumulate interesting data and some highlights are presented at the meeting. The sciences generated by flux networks in other continents have proven the worthiness of a global array of micrometeorological flux towers. It is our intent that the launch of KoFlux would encourage other scientists to initiate and

  2. Progress of the ECRH Upper Launcher design for ITER

    Strauss, D.; Aiello, G.; Bruschi, A.; Chavan, R.; Farina, D.; Figini, L.; Gagliardi, M.; Garcia, V.; Goodman, T.P.; Grossetti, G.; Heemskerk, C.; Henderson, M.A.; Kasparek, W.; Krause, A.; Landis, J.-D.; Meier, A.; Moro, A.; Platania, P.; Plaum, B.; Poli, E.

    2014-01-01

    The design of the ITER ECRH system provides 20 MW millimeter wave power for central plasma heating and MHD stabilization. The system consists of an array of 24 gyrotrons with power supplies coupled to a set of transmission lines guiding the beams to the four upper and the equatorial launcher. The front steering upper launcher design described herein has passed successfully the preliminary design review, and it is presently in the final design stage. The launcher consists of a millimeter wave system and steering mechanism with neutron shielding integrated into an upper port plug with the plasma facing blanket shield module (in-vessel) and a set of ex-vessel waveguides connecting the launcher to the transmission lines. Part of the transmission lines are the ultra-low loss CVD torus diamond windows and a shutter valve, a miter bend section and the feedthroughs integrated in the plug closure plate. These components are connected by corrugated waveguides and form together the first confinement system (FCS). In-vessel, the millimeter-wave system includes a quasi-optical beam propagation system including four mirror sets and a front steering mirror. The millimeter wave system is integrated into a specifically optimized upper port plug providing structural stability to withstand plasma disruption forces and the high heat load from the plasma side with a dedicated blanket shield module. A recent update in the ITER interface definition has resulted in the recession of the upper port plug first wall panels, which is now integrated into the design. Apart from the millimeter wave system the upper port plug houses also a set of shield blocks which provide neutron shielding. An overview of the actual ITER ECRH Upper Launcher is given together with some highlights of the design

  3. Upper Illinois River basin

    Friedel, Michael J.

    1998-01-01

    During the past 25 years, industry and government made large financial investments that resulted in better water quality across the Nation; however, many water-quality concerns remain. Following a 1986 pilot project, the U.S. Geological Survey began implementation of the National Water-Quality Assessment (NAWQA) Program in 1991. This program differs from other national water-quality assessment studies in that the NAWQA integrates monitoring of surface- and ground-water quality with the study of aquatic ecosystems. The goals of the NAWQA Program are to (1) describe current water-quality conditions for a large part of the Nation's freshwater streams and aquifers (water-bearing sediments and rocks), (2) describe how water quality is changing over time, and (3) improve our understanding of the primary natural and human factors affecting water quality.The Upper Illinois River Basin National Water- Quality Assessment (NAWQA) study will increase the scientific understanding of surface- and ground-water quality and the factors that affect water quality in the basin. The study also will provide information needed by water-resource managers to implement effective water-quality management actions and evaluate long-term changes in water quality.

  4. Flux expulsion and trapping in rotating discs of type II superconductors

    Boyer, R.; Leblanc, M.A.R.

    1977-01-01

    The magnetic flux rotating in step with a type II superconducting disc is measured with orthogonal pick up coils for various previous magnetic histories vs H 0 applied at right angles to the axis of rotation. For some initial magnetic states, flux expulsion, independent of the rate of rotation, occurs during the initial rotation. A simple model where flux lines leave the specimen against the magnetic pressure in the active region accounts for the observations. (author)

  5. The comparison of heat flux pattern on lower divertor in KSTAR

    Bang, Eunnam; Hong, Suk-Ho; Bak, JunGyo; Kim, Kyungmin; Kim, Hongtack; Kim, Hakkun; Yang, H.L.

    2015-01-01

    Highlights: • The heat flux on the lower divertor is higher than upper divertor. • The heat flux on OD is decreased with IVCP. • The heat flux on CD is decreased with RMP, but that on OD is increased. • Because the strike point was shifted from CD toward OD due to the RMP. - Abstract: The heat flux in KSTAR is estimated for various discharge conditions by using thermocouple arrays. The heat flux on the divertor is higher than that on inboard limiter or passive stabilizer by a factor of 2. Although the plasma configuration in KSTAR has been set to a double-null configuration, the heat flux on lower divertor is higher than that on upper divertor by 3–8 times, indicating a lower-single-null-like configuration. It is observed that the operation of the in-vessel cryo-pump (IVCP) changes the heat flux pattern significantly: When the IVCP was not operated, the heat fluxes on inboard divertor (ID), central divertor (CD) and outboard divertor (OD) were similar, but when the IVCP was operated, the heat fluxes on ID and CD were increased slightly and that on OD was decreased by 2–3 times. The heat flux on divertor was decreased from 35 to 26 kW/m"2 with the use of the resonant magnetic perturbation (RMP), especially that on CD was decreased by 2–4 times, while that on OD is increased by 2–3 times than without RMP. For the longest H-mode pulse of 22 s shot, the heat flux on lower OD was 73 kW/m"2, which is the maximum heat flux among the shots obtained in 2013 campaign.

  6. Multi-spectra Cosmic Ray Flux Measurement

    He, Xiaochun; Dayananda, Mathes

    2010-02-01

    The Earth's upper atmosphere is constantly bombarded by rain of charged particles known as primary cosmic rays. These primary cosmic rays will collide with the atmospheric molecules and create extensive secondary particles which shower downward to the surface of the Earth. In recent years, a few studies have been done regarding to the applications of the cosmic ray measurements and the correlations between the Earth's climate conditions and the cosmic ray fluxes [1,2,3]. Most of the particles, which reach to the surface of the Earth, are muons together with a small percentage of electrons, gammas, neutrons, etc. At Georgia State University, multiple cosmic ray particle detectors have been constructed to measure the fluxes and energy distributions of the secondary cosmic ray particles. In this presentation, we will briefly describe these prototype detectors and show the preliminary test results. Reference: [1] K.Borozdin, G.Hogan, C.Morris, W.Priedhorsky, A.Saunders, L.Shultz, M.Teasdale, Nature, Vol.422, 277 (2003). [2] L.V. Egorova, V. Ya Vovk, O.A. Troshichev, Journal of Atmospheric and Terrestrial Physics 62, 955-966 (2000). [3] Henrik Svensmark, Phy. Rev. Lett. 81, 5027 (1998). )

  7. Magnetic reconnection during eruptive magnetic flux ropes

    Mei, Z. X.; Keppens, R.; Roussev, I. I.; Lin, J.

    2017-08-01

    Aims: We perform a three-dimensional (3D) high resolution numerical simulation in isothermal magnetohydrodynamics to study the magnetic reconnection process in a current sheet (CS) formed during an eruption of a twisted magnetic flux rope (MFR). Because the twist distribution violates the Kruskal-Shafranov condition, the kink instability occurs, and the MFR is distorted. The centre part of the MFR loses its equilibrium and erupts upward, which leads to the formation of a 3D CS underneath it. Methods: In order to study the magnetic reconnection inside the CS in detail, mesh refinement has been used to reduce the numerical diffusion and we estimate a Lundquist number S = 104 in the vicinity of the CS. Results: The refined mesh allows us to resolve fine structures inside the 3D CS: a bifurcating sheet structure signaling the 3D generalization of Petschek slow shocks, some distorted-cylindrical substructures due to the tearing mode instabilities, and two turbulence regions near the upper and the lower tips of the CS. The topological characteristics of the MFR depend sensitively on the observer's viewing angle: it presents as a sigmoid structure, an outwardly expanding MFR with helical distortion, or a flare-CS-coronal mass ejection symbiosis as in 2D flux-rope models when observed from the top, the front, or the side. The movie associated to Fig. 2 is available at http://www.aanda.org

  8. Development of dual field magnetic flux leakage (MFL) inspection technology to detect mechanical damage.

    2013-03-01

    This report details the development and testing of a dual magnetization in-line inspection (ILI) : tool for detecting mechanical damage in operating pipelines, including the first field trials of a : fully operational dual-field magnetic flux leakage...

  9. Shawnee Mission's On-Line Cataloging System

    Ellen Wasby Miller

    1971-03-01

    Full Text Available An on-line cataloging pilot project for two elementary schools is discussed. The system components are 2740 terminals, upper-lower-case input, IBM's FASTER generalized software package, and usual cards/labels output. Reasons for choosing FASTER, software and hardware features, operating procedures, system performance and costs are detailed. Future expansion to cataloging 100,000 annual K-12 acquisitions, on-line circulation, retrospective conversion, and union book catalogs is set forth.

  10. From elementary flux modes to elementary flux vectors: Metabolic pathway analysis with arbitrary linear flux constraints

    Klamt, Steffen; Gerstl, Matthias P.; Jungreuthmayer, Christian; Mahadevan, Radhakrishnan; Müller, Stefan

    2017-01-01

    Elementary flux modes (EFMs) emerged as a formal concept to describe metabolic pathways and have become an established tool for constraint-based modeling and metabolic network analysis. EFMs are characteristic (support-minimal) vectors of the flux cone that contains all feasible steady-state flux vectors of a given metabolic network. EFMs account for (homogeneous) linear constraints arising from reaction irreversibilities and the assumption of steady state; however, other (inhomogeneous) linear constraints, such as minimal and maximal reaction rates frequently used by other constraint-based techniques (such as flux balance analysis [FBA]), cannot be directly integrated. These additional constraints further restrict the space of feasible flux vectors and turn the flux cone into a general flux polyhedron in which the concept of EFMs is not directly applicable anymore. For this reason, there has been a conceptual gap between EFM-based (pathway) analysis methods and linear optimization (FBA) techniques, as they operate on different geometric objects. One approach to overcome these limitations was proposed ten years ago and is based on the concept of elementary flux vectors (EFVs). Only recently has the community started to recognize the potential of EFVs for metabolic network analysis. In fact, EFVs exactly represent the conceptual development required to generalize the idea of EFMs from flux cones to flux polyhedra. This work aims to present a concise theoretical and practical introduction to EFVs that is accessible to a broad audience. We highlight the close relationship between EFMs and EFVs and demonstrate that almost all applications of EFMs (in flux cones) are possible for EFVs (in flux polyhedra) as well. In fact, certain properties can only be studied with EFVs. Thus, we conclude that EFVs provide a powerful and unifying framework for constraint-based modeling of metabolic networks. PMID:28406903

  11. Flow line asymmetric nonimaging concentrating optics

    Jiang, Lun; Winston, Roland

    2016-09-01

    Nonimaging Optics has shown that it achieves the theoretical limits by utilizing thermodynamic principles rather than conventional optics. Hence in this paper the condition of the "best" design are both defined and fulfilled in the framework of thermodynamic arguments, which we believe has profound consequences for the designs of thermal and even photovoltaic systems, even illumination and optical communication tasks. This new way of looking at the problem of efficient concentration depends on probabilities, geometric flux field and radiative heat transfer while "optics" in the conventional sense recedes into the background. Some of the new development of flow line designs will be introduced and the connection between the thermodynamics and flow line design will be officially formulated in the framework of geometric flux field. A new way of using geometric flux to design nonimaging optics will be introduced. And finally, we discuss the possibility of 3D ideal nonimaing optics.

  12. Momentum flux associated with gravity waves in the low-latitude troposphere

    S. R. Prabhakaran Nayar

    Full Text Available The vertical fluxes of horizontal momentum at tropospheric heights are calculated for four days, 25–28 August 1999. The mean zonal wind during these days show the presence of strong westward wind at the upper troposphere. Both the symmetric beam radar method and the power spectral method of evaluation of vertical flux of zonal and meridional momentum shows nearly the same result for quiet conditions. The temporal evolution of the momentum flux is estimated for a day with strong zonal shear and convection. These results indicate that on 28 August 1999, the strong downward vertical wind in the lower altitude range is associated with upward vertical flux of zonal momentum, and strong upward vertical wind is associated with downward vertical flux. Similarly, the strong shear in zonal wind is associated with the increase in negative values in vertical flux in the upper troposphere. Analysis of the role of wave periods in the transport of momentum flux indicates that the vertical momentum flux magnitude is not evenly distributed in all wave periods, but instead it peaks at certain wave periods in the range 10 to 100 min.

    Key words. Meteorology and atmospheric dynamics (convective process; tropical meteorology; precipitation

  13. Experimental search for a time-modulated muon flux from the direction of Cygnus X-3

    Worstell, W.A.

    1986-01-01

    Two underground experiments have recently reported detection of an anomalously large muon flux from the direction of the binary X-ray source cygnus X-3, with the 4.8-hour period characteristic of this source. A muon flux of the claimed magnitude, combined with constraints from surface observations, is inconsistent with the production of these muons by photons from Cygnus X-3 in normal air showers. This flux would require either unexpected photon interactions at very high energy (>5 TeV)( or a new type of neutral particle in the flux from Cygnus X-3. This thesis documents measurements with the HPW (Harvard-Purdue-Wisconsin) large underground water Cerenkov detector which do not confirm the claimed muon flux. The author places an upper limit on the flux of time-modulated muons from the direction of Cygnus X-3 of 5 x 10 -11 muons-cm -2 sec -1 at a vertical depth of 1450 MWE meters of water equivalent, with 90% confidence. This upper limit may be compared with the flux of 7 x 10 -11 muons-cm 2 sec -1 at a vertical depth of 1800 MWE which was claimed by another experiment. The HPW measurements are consistent with no anomalous muon flux from Cygnus X-3

  14. The inverse Numerical Computer Program FLUX-BOT for estimating Vertical Water Fluxes from Temperature Time-Series.

    Trauth, N.; Schmidt, C.; Munz, M.

    2016-12-01

    Heat as a natural tracer to quantify water fluxes between groundwater and surface water has evolved to a standard hydrological method. Typically, time series of temperatures in the surface water and in the sediment are observed and are subsequently evaluated by a vertical 1D representation of heat transport by advection and dispersion. Several analytical solutions as well as their implementation into user-friendly software exist in order to estimate water fluxes from the observed temperatures. Analytical solutions can be easily implemented but assumptions on the boundary conditions have to be made a priori, e.g. sinusoidal upper temperature boundary. Numerical models offer more flexibility and can handle temperature data which is characterized by irregular variations such as storm-event induced temperature changes and thus cannot readily be incorporated in analytical solutions. This also reduced the effort of data preprocessing such as the extraction of the diurnal temperature variation. We developed a software to estimate water FLUXes Based On Temperatures- FLUX-BOT. FLUX-BOT is a numerical code written in MATLAB which is intended to calculate vertical water fluxes in saturated sediments, based on the inversion of measured temperature time series observed at multiple depths. It applies a cell-centered Crank-Nicolson implicit finite difference scheme to solve the one-dimensional heat advection-conduction equation. Besides its core inverse numerical routines, FLUX-BOT includes functions visualizing the results and functions for performing uncertainty analysis. We provide applications of FLUX-BOT to generic as well as to measured temperature data to demonstrate its performance.

  15. Searching for the 3.5 keV Line in the Stacked Suzaku Observations of Galaxy Clusters

    Bulbul, Esra; Markevitch, Maxim; Foster, Adam; Miller, Eric; Bautz, Mark; Lowenstein, Mike; Randall, Scott W.; Smith, Randall K.

    2016-01-01

    We perform a detailed study of the stacked Suzaku observations of 47 galaxy clusters, spanning a redshift range of 0.01-0.45, to search for the unidentified 3.5 keV line. This sample provides an independent test for the previously detected line. We detect a 2sigma-significant spectral feature at 3.5 keV in the spectrum of the full sample. When the sample is divided into two subsamples (cool-core and non-cool core clusters), the cool-core subsample shows no statistically significant positive residuals at the line energy. A very weak (approx. 2sigma confidence) spectral feature at 3.5 keV is permitted by the data from the non-cool-core clusters sample. The upper limit on a neutrino decay mixing angle of sin(sup 2)(2theta) = 6.1 x 10(exp -11) from the full Suzaku sample is consistent with the previous detections in the stacked XMM-Newton sample of galaxy clusters (which had a higher statistical sensitivity to faint lines), M31, and Galactic center, at a 90% confidence level. However, the constraint from the present sample, which does not include the Perseus cluster, is in tension with previously reported line flux observed in the core of the Perseus cluster with XMM-Newton and Suzaku.

  16. Nuclear gamma ray lines from supernovae

    Jardim, J.O.D.

    1980-01-01

    From theoretical considerations of the behaviour of gamma ray line fluxes occurring after a supernova explosion, the 1.156 and 0.847 MeV lines are seen to be the most likely to be observed. The 1.156 MeV line has been previously observed by other investigators. Observations of the 0.847 MeV line, and 1.332, 1.173 and 0.059 MeV lines using a Ge(Li) telescope aboard a stratospheric balloon which was flown in Brazil in 1977 are reported. The observation using a NaI(Tl) detector of a line in the energy interval 1.5 - 1.6 MeV, which may be due to 0 18 (p,p') 0 18 sup (*) reaction is also reported. (Author) [pt

  17. Flux trapping in superconducting cavities

    Vallet, C.; Bolore, M.; Bonin, B.; Charrier, J.P.; Daillant, B.; Gratadour, J.; Koechlin, F.; Safa, H.

    1992-01-01

    The flux trapped in various field cooled Nb and Pb samples has been measured. For ambient fields smaller than 3 Gauss, 100% of the flux is trapped. The consequences of this result on the behavior of superconducting RF cavities are discussed. (author) 12 refs.; 2 figs

  18. Squeezing Flux Out of Fat

    Gonzalez-Franquesa, Alba; Patti, Mary-Elizabeth

    2018-01-01

    Merging transcriptomics or metabolomics data remains insufficient for metabolic flux estimation. Ramirez et al. integrate a genome-scale metabolic model with extracellular flux data to predict and validate metabolic differences between white and brown adipose tissue. This method allows both metab...

  19. Data Acquisition and Flux Calculations

    Rebmann, C.; Kolle, O; Heinesch, B

    2012-01-01

    In this chapter, the basic theory and the procedures used to obtain turbulent fluxes of energy, mass, and momentum with the eddy covariance technique will be detailed. This includes a description of data acquisition, pretreatment of high-frequency data and flux calculation....

  20. Potential Magnetic Field around a Helical Flux-rope Current Structure in the Solar Corona

    Petrie, G. J. D.

    2007-01-01

    We consider the potential magnetic field associated with a helical electric line current flow, idealizing the near-potential coronal field within which a highly localized twisted current structure is embedded. It is found that this field has a significant axial component off the helical magnetic axis where there is no current flow, such that the flux winds around the axis. The helical line current field, in including the effects of flux rope writhe, is therefore more topologically complex tha...

  1. Groundwater-derived nutrient inputs to the Upper Gulf of Thailand

    Burnett, William C.; Wattayakorn, Gullaya; Taniguchi, Makoto; Dulaiova, Henrieta; Sojisuporn, Pramot; Rungsupa, Sompop; Ishitobi, Tomotoshi

    2007-01-01

    We report here the first direct measurements of nutrient fluxes via groundwater discharge into the Upper Gulf of Thailand. Nutrient and standard oceanographic surveys were conducted during the wet and dry seasons along the Chao Phraya River, Estuary and out into the Upper Gulf of Thailand. Additional measurements in selected near-shore regions of the Gulf included manual and automatic seepage meter deployments, as well as nutrient evaluations of seepage and coastal waters. The river transects characterized the distribution of biogeochemical parameters in this highly contaminated urban environment. Seepage flux measurements together with nutrient analyses of seepage fluids were used to estimate nutrient fluxes via groundwater pathways for comparison to riverine fluxes. Our findings show that disseminated seepage of nutrient-rich mostly saline groundwater into the Upper Gulf of Thailand is significant. Estimated fluxes of dissolved inorganic nitrogen (DIN) supplied via groundwater discharge were 40-50% of that delivered by the Chao Phraya River, inorganic phosphate was 60-70%, and silica was 15-40%. Dissolved organic nitrogen (DON) and phosphorus (DOP) groundwater fluxes were also high at 30-40% and 30-130% of the river inputs, respectively. These observations are especially impressive since the comparison is being made to the river that is the largest source of fresh water into the Gulf of Thailand and flows directly through the megacity of Bangkok with high nutrient loadings from industrial and domestic sources.

  2. Solar variations and their influence on trends in upper stratospheric ozone and temperature

    Wuebbles, D.J.; Kinnison, D.E.; Lean, J.L.

    1990-10-01

    Over the past decade, knowledge of the magnitude and temporal structure of the variations in the sun's ultraviolet irradiance has increased steadily. A number of theoretical modeling studies have shown that changes in the solar ultraviolet flux during the 11-year solar cycle can have a significant effect on stratospheric ozone concentrations. With the exception of Brasseur et al., who examined a very broad range of solar flux variations, all of these studies assumed much larger changes in the ultraviolet flux than measurements now indicate. These studies either calculated the steady-state effect at solar maximum and solar minimum or assumed sinusoidal variations in the solar flux changes with time. It is now possible to narrow the uncertainty range of the expected effects on upper stratospheric ozone and temperature resulting from the 11-year solar cycle. A more accurate representation of the solar flux changes with time is used in this analysis, as compared to previous published studies. This study also evaluates the relative roles of solar flux variations and increasing concentrations of long-lived trace gases in determining the observed trends in upper stratospheric ozone and temperature. The LLNL two-dimensional chemical-radiative-transport model of the global atmosphere is used to evaluate the combined effects on the stratosphere from changes in solar ultraviolet irradiances and trace gas concentrations over the last several decades. Derived trends in upper stratospheric ozone concentrations and temperature are then compared with available analyses of ground-based and satellite measurements over this time period

  3. Solar proton fluxes since 1956

    Reedy, R.C.

    1977-01-01

    The fluxes of protons emitted during solar flares since 1956 were evaluated. The depth-versus-activity profiles of 56 Co in several lunar rocks are consistent with the solar-proton fluxes detected by experiments on several satellites. Only about 20% of the solar-proton-induced activities of 22 Na and 55 Fe in lunar rocks from early Apollo missions were produced by protons emitted from the sun during solar cycle 20 (1965--1975). The depth-versus-activity data for these radionuclides in several lunar rocks were used to determine the fluxes of protons during solar cycle 19 (1954--1964). The average proton fluxes for cycle 19 are about five times those for both the last million years and for cycle 20. These solar-proton flux variations correlate with changes in sunspot activity

  4. New upper limits for atmospheric constituents on Io

    Fink, U.; Larson, H. P.; Gautier, T. N., III

    1976-01-01

    A spectrum of Io from 0.86 to 2.7 microns with a resolution of 3.36 per cm and a signal to rms noise ratio of 120 is presented. No absorptions due to any atmospheric constituents on Io could be found in the spectrum. Upper limits of 0.12 cm-atm for NH3, 0.12 cm-atm for CH4, 0.4 cm-atm for N2O, and 24 cm-atm for H2S were determined. Laboratory spectra of ammonia frosts as a function of temperature were compared with the spectrum of Io and showed this frost not to be present at the surface of Io. A search for possible resonance lines of carbon, silicon, and sulfur, as well as the 1.08-micron line of helium, proved negative. Upper emission limits of 60, 18, 27, and 60 kilorayleighs, respectively, were established for these lines.

  5. VT Digital Line Graph Miscellaneous Transmission Lines

    Vermont Center for Geographic Information — (Link to Metadata) This datalayer is comprised of Miscellaineous Transmission Lines. Digital line graph (DLG) data are digital representations of cartographic...

  6. Upper limit for Poisson variable incorporating systematic uncertainties by Bayesian approach

    Zhu, Yongsheng

    2007-01-01

    To calculate the upper limit for the Poisson observable at given confidence level with inclusion of systematic uncertainties in background expectation and signal efficiency, formulations have been established along the line of Bayesian approach. A FORTRAN program, BPULE, has been developed to implement the upper limit calculation

  7. Fractional flux excitations and flux creep in a superconducting film

    Lyuksyutov, I.F.

    1995-01-01

    We consider the transport properties of a modulated superconducting film in a magnetic field parallel to the film. Modulation can be either intrinsic, due to the layered structure of the high-T c superconductors, or artificial, e.g. due to thickness modulation. This system has an infinite set ( >) of pinned phases. In the pinned phase the excitation of flux loops with a fractional number of flux quanta by the applied current j results in flux creep with a generated voltage V ∝ exp[-jo/j[. (orig.)

  8. CHROMOSPHERIC AND CORONAL WAVE GENERATION IN A MAGNETIC FLUX SHEATH

    Kato, Yoshiaki; Hansteen, Viggo; Gudiksen, Boris; Wedemeyer, Sven; Carlsson, Mats; Steiner, Oskar

    2016-01-01

    Using radiation magnetohydrodynamic simulations of the solar atmospheric layers from the upper convection zone to the lower corona, we investigate the self-consistent excitation of slow magneto-acoustic body waves (slow modes) in a magnetic flux concentration. We find that the convective downdrafts in the close surroundings of a two-dimensional flux slab “pump” the plasma inside it in the downward direction. This action produces a downflow inside the flux slab, which encompasses ever higher layers, causing an upwardly propagating rarefaction wave. The slow mode, excited by the adiabatic compression of the downflow near the optical surface, travels along the magnetic field in the upward direction at the tube speed. It develops into a shock wave at chromospheric heights, where it dissipates, lifts the transition region, and produces an offspring in the form of a compressive wave that propagates further into the corona. In the wake of downflows and propagating shock waves, the atmosphere inside the flux slab in the chromosphere and higher tends to oscillate with a period of ν ≈ 4 mHz. We conclude that this process of “magnetic pumping” is a most plausible mechanism for the direct generation of longitudinal chromospheric and coronal compressive waves within magnetic flux concentrations, and it may provide an important heat source in the chromosphere. It may also be responsible for certain types of dynamic fibrils.

  9. Ultrahigh Flux Thin Film Boiling Heat Transfer Through Nanoporous Membranes.

    Wang, Qingyang; Chen, Renkun

    2018-05-09

    Phase change heat transfer is fundamentally important for thermal energy conversion and management, such as in electronics with power density over 1 kW/cm 2 . The critical heat flux (CHF) of phase change heat transfer, either evaporation or boiling, is limited by vapor flux from the liquid-vapor interface, known as the upper limit of heat flux. This limit could in theory be greater than 1 kW/cm 2 on a planar surface, but its experimental realization has remained elusive. Here, we utilized nanoporous membranes to realize a new "thin film boiling" regime that resulted in an unprecedentedly high CHF of over 1.2 kW/cm 2 on a planar surface, which is within a factor of 4 of the theoretical limit, and can be increased to a higher value if mechanical strength of the membranes can be improved (demonstrated with 1.85 kW/cm 2 CHF in this work). The liquid supply is achieved through a simple nanoporous membrane that supports the liquid film where its thickness automatically decreases as heat flux increases. The thin film configuration reduces the conductive thermal resistance, leads to high frequency bubble departure, and provides separate liquid-vapor pathways, therefore significantly enhances the heat transfer. Our work provides a new nanostructuring approach to achieve ultrahigh heat flux in phase change heat transfer and will benefit both theoretical understanding and application in thermal management of high power devices of boiling heat transfer.

  10. CHROMOSPHERIC AND CORONAL WAVE GENERATION IN A MAGNETIC FLUX SHEATH

    Kato, Yoshiaki; Hansteen, Viggo; Gudiksen, Boris; Wedemeyer, Sven; Carlsson, Mats [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, NO-0315 Oslo (Norway); Steiner, Oskar, E-mail: yoshiaki.kato@astro.uio.no [Kiepenheuer-Institut für Sonnenphysik, Schöneckstrasse 6, D-79104 Freiburg (Germany)

    2016-08-10

    Using radiation magnetohydrodynamic simulations of the solar atmospheric layers from the upper convection zone to the lower corona, we investigate the self-consistent excitation of slow magneto-acoustic body waves (slow modes) in a magnetic flux concentration. We find that the convective downdrafts in the close surroundings of a two-dimensional flux slab “pump” the plasma inside it in the downward direction. This action produces a downflow inside the flux slab, which encompasses ever higher layers, causing an upwardly propagating rarefaction wave. The slow mode, excited by the adiabatic compression of the downflow near the optical surface, travels along the magnetic field in the upward direction at the tube speed. It develops into a shock wave at chromospheric heights, where it dissipates, lifts the transition region, and produces an offspring in the form of a compressive wave that propagates further into the corona. In the wake of downflows and propagating shock waves, the atmosphere inside the flux slab in the chromosphere and higher tends to oscillate with a period of ν ≈ 4 mHz. We conclude that this process of “magnetic pumping” is a most plausible mechanism for the direct generation of longitudinal chromospheric and coronal compressive waves within magnetic flux concentrations, and it may provide an important heat source in the chromosphere. It may also be responsible for certain types of dynamic fibrils.

  11. Upper lip changes and gingival exposure on smiling: vertical dimension analysis.

    Miron, Hagai; Calderon, Shlomo; Allon, Dror

    2012-01-01

    Our objectives were to evaluate and quantify upper lip soft-tissue changes in the vertical dimensions both at rest and at maximum smile, and to examine the correlation between upper labial vestibular attachment height and maxillary gingival exposure on smiling. Seventy-two volunteers (36 men, 36 women) aged 20 to 40 (mean, 30.49 years) were recruited for this study. For each subject, 9 measurements of upper lip position and maxillary incisor crown height at rest and in maximum smile were recorded. A statistically significant sexual dimorphism was apparent in most of the measured variables. Relaxed external upper lip length was 3.1 mm shorter in the women than in the men. The mean maxillary central incisor display at rest was 1.78 mm greater in the women than in the men. A high smile line was 2.5 times more prevalent in the women. The upper lip was shortened by 30% in subjects with a high smile line compared with 23% in subjects with a low smile line. The following findings were observed in subjects with a high smile pattern: (1) short upper lip length, (2) low smiling/resting upper lip length ratio, (3) inferior attachment of the upper labial vestibule, and (4) prominent upper lip vermilion. Copyright © 2012 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  12. Advances on geometric flux optical design method

    García-Botella, Ángel; Fernández-Balbuena, Antonio Álvarez; Vázquez, Daniel

    2017-09-01

    Nonimaging optics is focused on the study of methods to design concentrators or illuminators systems. It can be included in the area of photometry and radiometry and it is governed by the laws of geometrical optics. The field vector method, which starts with the definition of the irradiance vector E, is one of the techniques used in nonimaging optics. Called "Geometrical flux vector" it has provide ideal designs. The main property of this model is, its ability to estimate how radiant energy is transferred by the optical system, from the concepts of field line, flux tube and pseudopotential surface, overcoming traditional raytrace methods. Nevertheless this model has been developed only at an academic level, where characteristic optical parameters are ideal not real and the studied geometries are simple. The main objective of the present paper is the application of the vector field method to the analysis and design of real concentration and illumination systems. We propose the development of a calculation tool for optical simulations by vector field, using algorithms based on Fermat`s principle, as an alternative to traditional tools for optical simulations by raytrace, based on reflection and refraction law. This new tool provides, first, traditional simulations results: efficiency, illuminance/irradiance calculations, angular distribution of light- with lower computation time, photometrical information needs about a few tens of field lines, in comparison with million rays needed nowadays. On the other hand the tool will provides new information as vector field maps produced by the system, composed by field lines and quasipotential surfaces. We show our first results with the vector field simulation tool.

  13. A comprehensive biogeochemical record and annual flux estimates for the Sabaki River (Kenya)

    Marwick, Trent R.; Tamooh, Fredrick; Ogwoka, Bernard; Borges, Alberto V.; Darchambeau, François; Bouillon, Steven

    2018-03-01

    Inland waters impart considerable influence on nutrient cycling and budget estimates across local, regional and global scales, whilst anthropogenic pressures, such as rising populations and the appropriation of land and water resources, are undoubtedly modulating the flux of carbon (C), nitrogen (N) and phosphorus (P) between terrestrial biomes to inland waters, and the subsequent flux of these nutrients to the marine and atmospheric domains. Here, we present a 2-year biogeochemical record (October 2011-December 2013) at biweekly sampling resolution for the lower Sabaki River, Kenya, and provide estimates for suspended sediment and nutrient export fluxes from the lower Sabaki River under pre-dam conditions, and in light of the approved construction of the Thwake Multipurpose Dam on its upper reaches (Athi River). Erratic seasonal variation was typical for most parameters, with generally poor correlation between discharge and material concentrations, and stable isotope values of C (δ13C) and N (δ15N). Although high total suspended matter (TSM) concentrations are reported here (up to ˜ 3.8 g L-1), peak concentrations of TSM rarely coincided with peak discharge. The contribution of particulate organic C (POC) to the TSM pool indicates a wide biannual variation in suspended sediment load from OC poor (0.3 %) to OC rich (14.9 %), with the highest %POC occurring when discharge is Wet season flows (October-December and March-May) carried > 80 % of the total load for TSM (˜ 86 %), POC (˜ 89 %), dissolved organic carbon (DOC; ˜ 81 %), PN (˜ 89 %) and particulate phosphorus (TPP; ˜ 82 %), with > 50 % of each fraction exported during the long wet season (March-May). Our estimated sediment yield (85 Mg km-2 yr-1) is relatively low on the global scale and is considerably less than the recently reported average sediment yield of ˜ 630 Mg km-2 yr-1 for African river basins. Regardless, sediment and OC yields were all at least equivalent or greater than reported yields

  14. Heat flux solarimeter

    Sartarelli, A.; Vera, S.; Cyrulies, E. [Instituto de Desarrollo Humano, Univ. Nac. de Gral. Sarmiento (IDH, UNGS), Los Polvorines (Argentina); Echarri, R. [Instituto de Desarrollo Humano, Univ. Nac. de Gral. Sarmiento (IDH, UNGS), Los Polvorines (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Samson, I. [INTEC (Instituto Tecnologico Santo Domingo), Santo Domingo (Dominican Republic)

    2010-12-15

    The solarimeter presented in this work is easy to assemble. It is calibrated and its performance is validated by means of Hottel's method. Finally, the curves obtained with this solarimeter are compared to the ones obtained with a commercial solarimeter. This device is based on the evaluation of the heat flow in a metal rod. In consequence, measurements are not affected by ambient temperature variations. On the other hand, there is a linear relationship between the temperatures measured at the rod ends and the incident radiation, as can be concluded both from the theory of its operation and the calibration lines obtained. The results obtained from the global irradiance measurements in the area of Los Polvorines (Buenos Aires Province), together with a preliminary evaluation of the solarimeter's response time, are presented in this work. (author)

  15. Regularized Biot-Savart Laws for Modeling Magnetic Flux Ropes

    Titov, Viacheslav; Downs, Cooper; Mikic, Zoran; Torok, Tibor; Linker, Jon A.

    2017-08-01

    Many existing models assume that magnetic flux ropes play a key role in solar flares and coronal mass ejections (CMEs). It is therefore important to develop efficient methods for constructing flux-rope configurations constrained by observed magnetic data and the initial morphology of CMEs. As our new step in this direction, we have derived and implemented a compact analytical form that represents the magnetic field of a thin flux rope with an axis of arbitrary shape and a circular cross-section. This form implies that the flux rope carries axial current I and axial flux F, so that the respective magnetic field is a curl of the sum of toroidal and poloidal vector potentials proportional to I and F, respectively. The vector potentials are expressed in terms of Biot-Savart laws whose kernels are regularized at the rope axis. We regularized them in such a way that for a straight-line axis the form provides a cylindrical force-free flux rope with a parabolic profile of the axial current density. So far, we set the shape of the rope axis by tracking the polarity inversion lines of observed magnetograms and estimating its height and other parameters of the rope from a calculated potential field above these lines. In spite of this heuristic approach, we were able to successfully construct pre-eruption configurations for the 2009 February13 and 2011 October 1 CME events. These applications demonstrate that our regularized Biot-Savart laws are indeed a very flexible and efficient method for energizing initial configurations in MHD simulations of CMEs. We discuss possible ways of optimizing the axis paths and other extensions of the method in order to make it more useful and robust.Research supported by NSF, NASA's HSR and LWS Programs, and AFOSR.

  16. Thermomechanical simulation of WEST actively cooled upper divertor

    Batal, T.; Richou, M.; Guilhem, D.; Firdaouss, M.; Larroque, S.; Ferlay, F.; Missirlian, M.; Bucalossi, J.

    2016-01-01

    The Tore Supra tokamak is being transformed in an x-point divertor fusion device in the frame of the WEST (W-for tungsten-Environment in Steady-state Tokamak) project, launched in support to the ITER tungsten divertor strategy. The WEST project aims to test ITER-like W monoblock Plasma Facing Units (PFU). This ITER-like divertor will be tested under long plasma discharge up to 1000 s, with high heat flux density up to 20 MW/m 2 . This paper presents the results of ANSYS thermal-structural simulations of the WEST upper divertor. The upper divertor is made of twelve 30° sectors, each one composed of 38 PFU. The PFUs are actively cooled CuCrZr heat sinks and the incidence surface is coated with a thin tungsten layer. The fixing system is made of pins engaged in slotted holes. Besides, the fixing system of the sector assembly is the same as WEST lower divertor, so one upper divertor sector can be used indifferently in upper or Lower position during transitional operation phases in WEST. The total surface of the upper divertor is 8 m 2 , and it has to be able to extract up to 4 MW in steady-state, with peak heat flux values up to 8 MW/m 2 . The fixing system was designed to handle structural loads such as forces and torques resulting from halo and eddy current, respectively, especially during disruptions and Vertical Displacement Event (VDE). The torque resulting from eddy current is first calculated thanks to an internal CEA ANSYS APDL routine. Then the ANSYS structural and thermal-structural simulations of the PFU are presented, and its design is validated thanks to A-level RCC-MRx criteria. Finally, the most conservative load case is determined in order to validate the design of the pins and the support structure.

  17. Thermomechanical simulation of WEST actively cooled upper divertor

    Batal, T., E-mail: tristan.batal@cea.fr; Richou, M.; Guilhem, D.; Firdaouss, M.; Larroque, S.; Ferlay, F.; Missirlian, M.; Bucalossi, J.

    2016-11-15

    The Tore Supra tokamak is being transformed in an x-point divertor fusion device in the frame of the WEST (W-for tungsten-Environment in Steady-state Tokamak) project, launched in support to the ITER tungsten divertor strategy. The WEST project aims to test ITER-like W monoblock Plasma Facing Units (PFU). This ITER-like divertor will be tested under long plasma discharge up to 1000 s, with high heat flux density up to 20 MW/m{sup 2}. This paper presents the results of ANSYS thermal-structural simulations of the WEST upper divertor. The upper divertor is made of twelve 30° sectors, each one composed of 38 PFU. The PFUs are actively cooled CuCrZr heat sinks and the incidence surface is coated with a thin tungsten layer. The fixing system is made of pins engaged in slotted holes. Besides, the fixing system of the sector assembly is the same as WEST lower divertor, so one upper divertor sector can be used indifferently in upper or Lower position during transitional operation phases in WEST. The total surface of the upper divertor is 8 m{sup 2}, and it has to be able to extract up to 4 MW in steady-state, with peak heat flux values up to 8 MW/m{sup 2}. The fixing system was designed to handle structural loads such as forces and torques resulting from halo and eddy current, respectively, especially during disruptions and Vertical Displacement Event (VDE). The torque resulting from eddy current is first calculated thanks to an internal CEA ANSYS APDL routine. Then the ANSYS structural and thermal-structural simulations of the PFU are presented, and its design is validated thanks to A-level RCC-MRx criteria. Finally, the most conservative load case is determined in order to validate the design of the pins and the support structure.

  18. New upper limits on the local metagalactic ionizing radiation density

    Vogel, Stuart N.; Weymann, Ray; Rauch, Michael; Hamilton, Tom

    1995-01-01

    We have obtained H-alpha observations with the Maryland-Caltech Fabry-Perot Spectrometer attached to the Cassegrain focus of the 1.5 m telescope at Palomer Observatory in order to set limits on the number of ionizing photons from the local metagalactic radiation field. We have observed the SW component of the Haynes-Giovanelli cloud H I 1225+01, an intergalactic cloud which should be optimum for measuring the metagalactic flux because it is nearly opaque to ionizing photons, it does not appear to be significantly shielded from the metagalactic radiation field, and the limits on embedded or nearby ionizing sources are unusually low. For the area of the cloud with an H I column density greater than 10(exp 19)/sq cm we set a 2 sigma limit of 1.1 x 10(exp -19) ergs/sq cm/s/sq arcsec (20 mR) for the surface brightness of diffuse H-alpha. This implies a 2 sigma upper limit on the incident one-sided ionizing flux of Phi(sub ex) is less than 3 x 10(exp 4)/sq cm/s. For a radiation field of the form J(sub nu) is approximately nu(exp -1.4), this yields a firm 2 sigma upper limit on the local metagalactic photoionization rate of Gamma is less than 2 x 10(exp -13)/s, and an upper limit for the radiation field J(sub nu) at the Lyman limit of J(sub nu0) is less than 8 x 10(exp -23) ergs/sq cm/Hz/sr. We discuss previous efforts to constrain the metagalactic ionizing flux using H-alpha surface brightness observations and also other methods, and conclude that our result places the firmest upper limit on this flux. We also observed the 7 min diameter region centered on 3C 273 in which H-alpha emission at a velocity of approximately 1700 km/s was initially reported by Williams and Schommer. In agreement with T. B. Williams (private communication) we find the initial detection was spurious. We obtain a 2 sigma upper limit of 1.8 x 10(exp -19) ergs/sq cm/s/sq arcsec (32 mR) for the mean surface brightness of diffuse H-alpha, about a factor of 6 below the published value.

  19. Monte Carlo surface flux tallies

    Favorite, Jeffrey A.

    2010-01-01

    Particle fluxes on surfaces are difficult to calculate with Monte Carlo codes because the score requires a division by the surface-crossing angle cosine, and grazing angles lead to inaccuracies. We revisit the standard practice of dividing by half of a cosine 'cutoff' for particles whose surface-crossing cosines are below the cutoff. The theory behind this approximation is sound, but the application of the theory to all possible situations does not account for two implicit assumptions: (1) the grazing band must be symmetric about 0, and (2) a single linear expansion for the angular flux must be applied in the entire grazing band. These assumptions are violated in common circumstances; for example, for separate in-going and out-going flux tallies on internal surfaces, and for out-going flux tallies on external surfaces. In some situations, dividing by two-thirds of the cosine cutoff is more appropriate. If users were able to control both the cosine cutoff and the substitute value, they could use these parameters to make accurate surface flux tallies. The procedure is demonstrated in a test problem in which Monte Carlo surface fluxes in cosine bins are converted to angular fluxes and compared with the results of a discrete ordinates calculation.

  20. Drop evaporation and triple line dynamics

    Sobac, Benjamin; Brutin, David; Gavillet, Jerome; Université de Provence Team; Cea Liten Team

    2011-03-01

    Sessile drop evaporation is a phenomenon commonly came across in nature or in industry with cooling, paintings or DNA mapping. However, the evaporation of a drop deposited on a substrate is not completely understood due to the complexity of the problem. Here we investigate, with several nano-coating of the substrate (PTFE, SiOx, SiOc and CF), the influence of the dynamic of the triple line on the evaporation process. The experiment consists in analyzing simultaneously the motion of the triple line, the kinetics of evaporation, the internal thermal motion and the heat and mass transfer. Measurements of temperature, heat-flux and visualizations with visible and infrared cameras are performed. The dynamics of the evaporative heat flux appears clearly different depending of the motion of the triple line

  1. Coordinated ATS 5 electron flux and simultaneous auroral observations

    Mende, S.B.; Shelley, E.G.

    1976-01-01

    All-sky camera (ASCA) observations were made at the field line conjugate of the ATS 5 satellite. The field of view of these cameras covered the region of the magnetosphere from L=5 to L=11 at the approximate longitude of the ATS field line conjugate. With this coverage, definite statements can be made concerning the correlation of the auroras observed by the ASCA's and the magnetospheric trapped fluxes. In general, auroral forms are not simply correlated with the synchronous altitude electron fluxes. The presence of hot plasma at the ATS 5 satellite is a necessary but not sufficient condition for the occurrence of local auroras. On quiet days the hot plasma does not penetrate into the magnetosphere far enough to reach the ATS 5 orbit. Under these conditions, no auroras are observed at the field line conjugate, but auroras are usually observed on higher-latitude field lines. On more disturbed days, auroral arcs are observed at lower latitudes when the plasma sheet penetrates into the ATS 5 orbit. There is no general correlation between the intensity of the trapped electron fluxes observed by ATS 5 and the intensity of auroras observed by the ASCA's. Auroral displays exhibit very fast fluctuations, whereas the ATS 5 electron fluxes change on a much slower time scale. However, significant qualitative correlation between the ASCA data and the trapped fluxes is observed when a local plasma injection event occurs near ATS 5. The clearest signature of the injection event is magnetic and is most pronounced as a recovery of a negative bay in the north-south component of the field at the ATS 5. The local injection generally produces structured auroras such as breakup events and sometimes westward-traveling surges. A significant correlation is observed with the intensification of a diffuse uniform glow accompanying the structured auroral activity

  2. A Link Between X-ray Emission Lines and Radio Jets in 4U 1630-47?

    Neilsen, Joseph; Coriat, Mickaël; Fender, Rob; Lee, Julia C.; Ponti, Gabriele; Tzioumis, A.; Edwards, Phillip; Broderick, Jess

    2014-06-01

    Recently, Díaz Trigo et al. reported an XMM-Newton detection of relativistically Doppler-shifted emission lines associated with steep-spectrum radio emission in the stellar-mass black hole candidate 4U 1630-47 during its 2012 outburst. They interpreted these lines as indicative of a baryonic jet launched by the accretion disk. We present a search for the same lines earlier in the same outburst using high-resolution X-ray spectra from the Chandra HETGS. While our observations (eight months prior to the XMM-Newton campaign) also coincide with detections of steep spectrum radio emission by the Australia Telescope Compact Array, we find a strong disk wind but no evidence for any relativistic X-ray emission lines. Indeed, despite ˜5× brighter radio emission, our Chandra spectra allow us to place an upper limit on the flux in the blueshifted Fe XXVI line that is ˜20× weaker than the line observed by Díaz Trigo et al. Thus we can conclusively say that radio emission is not universally associated with relativistically Doppler-shifted emission lines in 4U 1630-47. We explore several scenarios that could explain our differing results, including variations in the geometry of the jet or a mass-loading process or jet baryon content that evolves with the accretion state of the black hole. We also consider the possibility that the radio emission arises in an interaction between a jet and the nearby ISM, in which case the X-ray emission lines might be unrelated to the radio emission.

  3. Flux creep characteristics in high-temperature superconductors

    Zeldov, E.; Amer, N.M.; Koren, G.; Gupta, A.; McElfresh, M.W.; Gambino, R.J.

    1990-01-01

    We describe the voltage-current characteristics of YBa 2 Cu 3 O 7-δ epitaxial films within the flux creep model in a manner consistent with the resistive transition behavior. The magnitude of the activation energy, and its temperature and magnetic field dependences, are readily derived from the experimentally observed power law characteristics and show a (1-T/T c ) 3/2 type of behavior near T c . The activation energy is a nonlinear function of the current density and it enables the determination of the shape of the flux line potential well

  4. Measuring Fast Calcium Fluxes in Cardiomyocytes

    Golebiewska, Urszula; Scarlata, Suzanne

    2011-01-01

    Cardiomyocytes have multiple Ca2+ fluxes of varying duration that work together to optimize function 1,2. Changes in Ca2+ activity in response to extracellular agents is predominantly regulated by the phospholipase Cβ- Gαq pathway localized on the plasma membrane which is stimulated by agents such as acetylcholine 3,4. We have recently found that plasma membrane protein domains called caveolae5,6 can entrap activated Gαq7. This entrapment has the effect of stabilizing the activated state of Gαq and resulting in prolonged Ca2+ signals in cardiomyocytes and other cell types8. We uncovered this surprising result by measuring dynamic calcium responses on a fast scale in living cardiomyocytes. Briefly, cells are loaded with a fluorescent Ca2+ indicator. In our studies, we used Ca2+ Green (Invitrogen, Inc.) which exhibits an increase in fluorescence emission intensity upon binding of calcium ions. The fluorescence intensity is then recorded for using a line-scan mode of a laser scanning confocal microscope. This method allows rapid acquisition of the time course of fluorescence intensity in pixels along a selected line, producing several hundreds of time traces on the microsecond time scale. These very fast traces are transferred into excel and then into Sigmaplot for analysis, and are compared to traces obtained for electronic noise, free dye, and other controls. To dissect Ca2+ responses of different flux rates, we performed a histogram analysis that binned pixel intensities with time. Binning allows us to group over 500 traces of scans and visualize the compiled results spatially and temporally on a single plot. Thus, the slow Ca2+ waves that are difficult to discern when the scans are overlaid due to different peak placement and noise, can be readily seen in the binned histograms. Very fast fluxes in the time scale of the measurement show a narrow distribution of intensities in the very short time bins whereas longer Ca2+ waves show binned data with a broad

  5. The U-line line balancing problem

    Miltenburg, G.J.; Wijngaard, J.

    1994-01-01

    The traditional line balancing (LB) problem considers a production line in which stations are arranged consecutively in a line. A balance is determined by grouping tasks into stations while moving forward (or backward) through a precedence network. Recently many production lines are being arranged

  6. Recent interstellar molecular line work

    Winnewisser, G.

    1975-01-01

    A summary of recent interstellar molecular line work is presented. Transitions of the following molecules have been detected in Sgr B2: Vinylcyanide, H 2 C 2 HCN, formic acid, HCOOH, dimethyl ether (CH 3 ) 2 O and isotopically labelled cyanoacetylene- 13 C,HC 13 CCN and HCC 13 CN. The data on cyanoacetylene give an upper limit to the abundance ratio 12 C/ 13 C of 36 +- 5. A short discussion of the interstellar chemistry leads to the conclusion that hydrocarbons such as acetylene, HCCH, ethylen, H 2 CCH 2 and ethane H 3 CCH 3 should be present in interstellar clouds. 13 refs

  7. Spectroscopy of chromospheric lines of giants in the globular cluster

    Dupree, A. K.; Hartmann, Lee; Smith, Graeme H.; Rodgers, A. W.; Roberts, W. H.; Zucker, D. B.

    1994-01-01

    Spectroscopic observations of chromospheric transitions (Mg II, H-alpha, and Ca II K) from two red giants (A31 and A59) in the globular cluster NGC 6572 were made with the Goddard High Resolution Spectrograph on the Hubble Space Telescope and the coude spectrograph of the 1.9 m telescope at the Mount Stromlo Observatory. These measurements give evidence for chromospheric activity and outward motions within the atmospheres. The surface flux of the Mg II emission is comparable to that in disk population giants of similar (B-V) color. The Mg II profiles are asymmetric, which is most likely caused by absorption in an expanding stellar atmosphere and/or by possible interstellar features. Notches are found in the core of the H-alpha line of A59, which are similar to those found in Cepheids. This suggests that shocks are present in the atmosphere of A59 and indicates that hydrodynamic phenomena are influencing the levvel of chromospheric emission and producing upper atmospheric motions which may lead to mass loss.

  8. Detection of 12 micron Mg I and OH lines in stellar spectra

    Jennings, D. E.; Deming, D.; Wiedemann, G. R.; Keady, J. J.

    1986-01-01

    Infrared lines of Mg I and OH have been detected in stellar spectra near 12.3 microns. The Mg I 7i-6h transition was seen in Alpha Ori and Alpha Tau, and the R2e(23.5) and R1f(24.5) transitions of OH were seen in Alpha Ori. All lines appear in absorption, in contrast to the solar spectrum where the Mg I line shows a prominent emission core. The lack of emission in these low surface gravity stars is due to a greatly reduced volume recombination rate for the high-n states of Mg I, which is not fully compensated by the increased chromospheric scale height. The OH equivalent widths are sensitive to the temperature structure of the upper photosphere of Alpha Ori, and they indicate that the photosphere near tau 5000 of about 10 to the -5th is approximately 100 K hotter than is given by flux constant models. The OH measurements agree more closely with the 1981 semiemprical model of Basri, Linsky, and Eriksson (1981), which is based on Ca II and Mg II ultraviolet features.

  9. OXYGEN METALLICITY DETERMINATIONS FROM OPTICAL EMISSION LINES IN EARLY-TYPE GALAXIES

    Athey, Alex E.; Bregman, Joel N.

    2009-01-01

    We measured the oxygen abundances of the warm (T ∼ 10 4 K) phase of gas in seven early-type galaxies through long-slit observations. A template spectra was constructed from galaxies void of warm gas and subtracted from the emission-line galaxies, allowing for a clean measurement of the nebular lines. The ratios of the emission lines are consistent with photoionization, which likely originates from the ultraviolet flux of postasymototic giant branch stars. We employ H II region photoionization models to determine a mean oxygen metallicity of 1.01 ± 0.50 solar for the warm interstellar medium (ISM) in this sample. This warm ISM 0.5-1.5 solar metallicity is consistent with modern determinations of the metallicity in the hot (T ∼ 10 6 -10 7 K) ISM and the upper range of this warm ISM metallicity is consistent with stellar population metallicity determinations. A solar metallicity of the warm ISM favors an internal origin for the warm ISM such as asymptotic giant branch mass loss within the galaxy.

  10. Are ghost surfaces quadratic-flux-minimizing?

    Hudson, S.R.; Dewar, R.L.

    2009-01-01

    Two candidates for 'almost-invariant' toroidal surfaces passing through magnetic islands, namely quadratic-flux-minimizing (QFMin) surfaces and ghost surfaces, use families of periodic pseudo-orbits (i.e. paths for which the action is not exactly extremal). QFMin pseudo-orbits, which are coordinate-dependent, are field lines obtained from a modified magnetic field, and ghost-surface pseudo-orbits are obtained by displacing closed field lines in the direction of steepest descent of magnetic action, ∫A.dl. A generalized Hamiltonian definition of ghost surfaces is given and specialized to the usual Lagrangian definition. A modified Hamilton's Principle is introduced that allows the use of Lagrangian integration for calculation of the QFMin pseudo-orbits. Numerical calculations show QFMin and Lagrangian ghost surfaces give very similar results for a chaotic magnetic field perturbed from an integrable case, and this is explained using a perturbative construction of an auxiliary poloidal angle for which QFMin and Lagrangian ghost surfaces are the same up to second order. While presented in the context of 3-dimensional magnetic field line systems, the concepts are applicable to defining almost-invariant tori in other 11/2 degree-of-freedom nonintegrable Lagrangian/Hamiltonian systems.

  11. Using robustness and preferred locations of archeomagnetic flux patches to constrain the physics of the core

    Terra-Nova, F.; Amit, H.; Hartmann, G. A.; Trindade, R. I. F.

    2017-12-01

    Archaeomagnetic field models cover longer timescales than historical models and may therefore resolve the motion of geomagnetic features on the core-mantle boundary (CMB) in a more meaningful statistical sense. Here we perform a detailed appraisal of archaeomagnetic field models to infer some aspects of the physics of the outer core. We characterize and compare the identification and tracking of reversed flux patches (RFPs) in order to assess the RFPs robustness. We find similar behaviour within a family of models but differences among different families, suggesting that modelling strategy is more influential than data set. Similarities involve recurrent positions of RFPs, but no preferred direction of motion is found. The tracking of normal flux patches shows similar qualitative behaviour confirming that RFPs identification and tracking is not strongly biased by their relative weakness. We also compare the tracking of RFPs with that of the historical field model gufm1 and with seismic anomalies of the lowermost mantle to explore the possibility that RFPs have preferred locations prescribed by lower mantle lateral heterogeneity. The archaeomagnetic field model that most resembles the historical field is interpreted in terms of core dynamics and core-mantle thermal interactions. This model exhibits correlation between RFPs and low seismic shear velocity in co-latitude and a shift in longitude. These results shed light on core processes, in particular we infer toroidal field lines with azimuthal orientation below the CMB and large fluid upwelling structures with a width of about 80° (Africa) and 110° (Pacific) at the top of the core. Finally, similar preferred locations of RFPs in the past 9 and 3 kyr of the same archaeomagnetic field model suggest that a 3 kyr period is sufficiently long to reliably detect mantle control on core dynamics. This allows estimating an upper bound of 220-310 km for the magnetic boundary layer thickness below the CMB.

  12. Chloride flux in phagocytes.

    Wang, Guoshun

    2016-09-01

    Phagocytes, such as neutrophils and macrophages, engulf microbes into phagosomes and launch chemical attacks to kill and degrade them. Such a critical innate immune function necessitates ion participation. Chloride, the most abundant anion in the human body, is an indispensable constituent of the myeloperoxidase (MPO)-H2 O2 -halide system that produces the potent microbicide hypochlorous acid (HOCl). It also serves as a balancing ion to set membrane potentials, optimize cytosolic and phagosomal pH, and regulate phagosomal enzymatic activities. Deficient supply of this anion to or defective attainment of this anion by phagocytes is linked to innate immune defects. However, how phagocytes acquire chloride from their residing environment especially when they are deployed to epithelium-lined lumens, and how chloride is intracellularly transported to phagosomes remain largely unknown. This review article will provide an overview of chloride protein carriers, potential mechanisms for phagocytic chloride preservation and acquisition, intracellular chloride supply to phagosomes for oxidant production, and methods to measure chloride levels in phagocytes and their phagosomes. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Extensive upper respiratory tract sarcoidosis

    Soares, Mafalda Trindade; Sousa, Carolina; Garanito, Luísa; Freire, Filipe

    2016-01-01

    Sarcoidosis is a chronic granulomatous disease of unknown aetiology. It can affect any part of the organism, although the lung is the most frequently affected organ. Upper airway involvement is rare, particularly if isolated. Sarcoidosis is a diagnosis of exclusion, established by histological evidence of non-caseating granulomas and the absence of other granulomatous diseases. The authors report a case of a man with sarcoidosis manifesting as a chronic inflammatory stenotic condition of the upper respiratory tract and trachea. PMID:27090537

  14. PEARS Emission Line Galaxies

    Pirzkal, Nor; Rothberg, Barry; Ly, Chun; Rhoads, James E.; Malhotra, Sangeeta; Grogin, Norman A.; Dahlen, Tomas; Meurer, Gerhardt R.; Walsh, Jeremy; Hathi, Nimish P.; hide

    2012-01-01

    We present a full analysis of the Probing Evolution And Reionization Spectroscopically (PEARS) slitless grism spectroscopic data obtained vl'ith the Advanced Camera for Surveys on HST. PEARS covers fields within both the Great Observatories Origins Deep Survey (GOODS) North and South fields, making it ideal as a random surveY of galaxies, as well as the availability of a wide variety of ancillary observations to support the spectroscopic results. Using the PEARS data we are able to identify star forming galaxies within the redshift volume 0 galaxies down to a limiting flux of approx 10 - 18 erg/s/sq cm . The ELRs have also been compared to the properties of the host galaxy, including morphology, luminosity, and mass. From this analysis we find three key results: 1) The computed line luminosities show evidence of a flattening in the luminosity function with increasing redshift; 2) The star forming systems show evidence of disturbed morphologies, with star formation occurring predominantly within one effective (half-light) radius. However, the morphologies show no correlation with host stellar mass; and 3) The number density of star forming galaxies with M(*) >= 10(exp 9) Solar M decreases by an order of magnitude at z<=0.5 relative to the number at 0.5 < z < 0.9 in support of the argument for galaxy downsizing.

  15. Extracting limits for the difuse non-electron neutrino flux from SNO data

    Miguez, B.S.R.; Kemp, E.; Peres, O.L.G. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Fisica Gleb Wataghin

    2009-07-01

    Full text. There is a prediction of a diffuse neutrino flux yield from the time integration of all supernova already exploded in the past governed by stellar formation and supernovae occurrence rates. The spectral characteristics of these neutrinos differ from those from recent supernovae mainly in two features: the reduction in their fluxes and their energy 'redshift' due the expansion of the universe. Thus, despite the fact that one single supernova is a transient state, their cumulative effect produces a steady flux of diffuse neutrinos everywhere in universe. These neutrinos have never been observed before. Only upper limits on their fluxes have been reported by the collaborations operating neutrino telescopes. Recently the SNO experiment have made an analysis where the total flux of diffuse electron neutrinos has an upper limit of phi{sub e} <= 61-93 cm{sup -2} s{sup -1}, depending on a specific supernova model. At the present, the best limit for the diffuse flux of non-electron neutrinos is phi{sub x} <= 10{sub 4} cm{sup -2} s{sup -1}, resulted from an analysis of the Super-Kamiokande data. In this work we have extended the SNO analysis including the elastic scattering on electrons via neutral current interactions to extract information on diffuse flux of the non-electron neutrino flavours (i.e. muon and tauon neutrinos). We make a comparison among our results and others from different experiments (LVD, SK, LSD). (author)

  16. Flux flow, pinning, and resistive behavior in superconducting networks

    Teitel, S.

    1991-10-01

    We have studied the behavior of fluctuation effects in superconducting systems using numerical simulations of XY and Coulomb gas models. Flux flow resistance in two dimensional Josephson junction arrays has been calculated, and related to correlations in vortex structure. Randomness has been introduced, and its effects on the superconducting transition, and vortex mobility, have been studied. We find that randomness destroys phase coherence, yet the randomness induced pinning reduces flux flow resistance at low temperatures. Vortex line fluctuations in high temperature superconductors have been studied using a three dimensional XY model. We have considered the melting of the vortex line lattice, and the entanglement and cutting of vortex lines in the vortex line liquid phase. Vortex line entangling and cutting appear to occur on the same length scales in the liquid phase. The vortex structure function has been calculated and from it, elastic properties of the vortex line liquid have been inferred. The two dimensional classical Coulomb gas, where charges map onto vortices in the superconducting system, has been simulated. The melting transitions of ordered charge (vortex) lattices have been studied, and we find evidence that these transitions do not have the critical behavior expected from standard symmetry analysis

  17. Conical electromagnetic radiation flux concentrator

    Miller, E. R.

    1972-01-01

    Concentrator provides method of concentrating a beam of electromagnetic radiation into a smaller beam, presenting a higher flux density. Smaller beam may be made larger by sending radiation through the device in the reverse direction.

  18. Physics of Magnetic Flux Ropes

    Priest, E R; Lee, L C

    1990-01-01

    The American Geophysical Union Chapman Conference on the Physics of Magnetic Flux Ropes was held at the Hamilton Princess Hotel, Hamilton, Bermuda on March 27–31, 1989. Topics discussed ranged from solar flux ropes, such as photospheric flux tubes, coronal loops and prominences, to flux ropes in the solar wind, in planetary ionospheres, at the Earth's magnetopause, in the geomagnetic tail and deep in the Earth's magnetosphere. Papers presented at that conference form the nucleus of this book, but the book is more than just a proceedings of the conference. We have solicited articles from all interested in this topic. Thus, there is some material in the book not discussed at the conference. Even in the case of papers presented at the conference, there is generally a much more detailed and rigorous presentation than was possible in the time allowed by the oral and poster presentations.

  19. Notes on neutron flux measurement

    Alcala Ruiz, F.

    1984-01-01

    The main purpose of this work is to get an useful guide to carry out topical neutron flux measurements. Although the foil activation technique is used in the majority of the cases, other techniques, such as those based on fission chambers and self-powered neutron detectors, are also shown. Special interest is given to the description and application of corrections on the measurement of relative and absolute induced activities by several types of detectors (scintillators, G-M and gas proportional counters). The thermal arid epithermal neutron fluxes, as determined in this work, are conventional or effective (West cots fluxes), which are extensively used by the reactor experimentalists; however, we also give some expressions where they are related to the integrated neutron fluxes, which are used in neutron calculations. (Author) 16 refs

  20. Specification of ROP flux shape

    Min, Byung Joo; Gray, A.

    1997-06-01

    The CANDU 9 480/SEU core uses 0.9% SEU (Slightly Enriched Uranium) fuel. The use f SEU fuel enables the reactor to increase the radial power form factor from 0.865, which is typical in current natural uranium CANDU reactors, to 0.97 in the nominal CANDU 9 480/SEU core. The difference is a 12% increase in reactor power. An additional 5% increase can be achieved due to a reduced refuelling ripple. The channel power limits were also increased by 3% for a total reactor power increase of 20%. This report describes the calculation of neutron flux distributions in the CANDU 9 480/SEU core under conditions specified by the C and I engineers. The RFSP code was used to calculate of neutron flux shapes for ROP analysis. Detailed flux values at numerous potential detector sites were calculated for each flux shape. (author). 6 tabs., 70 figs., 4 refs

  1. Specification of ROP flux shape

    Min, Byung Joo [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); Gray, A [Atomic Energy of Canada Ltd., Chalk River, ON (Canada)

    1997-06-01

    The CANDU 9 480/SEU core uses 0.9% SEU (Slightly Enriched Uranium) fuel. The use f SEU fuel enables the reactor to increase the radial power form factor from 0.865, which is typical in current natural uranium CANDU reactors, to 0.97 in the nominal CANDU 9 480/SEU core. The difference is a 12% increase in reactor power. An additional 5% increase can be achieved due to a reduced refuelling ripple. The channel power limits were also increased by 3% for a total reactor power increase of 20%. This report describes the calculation of neutron flux distributions in the CANDU 9 480/SEU core under conditions specified by the C and I engineers. The RFSP code was used to calculate of neutron flux shapes for ROP analysis. Detailed flux values at numerous potential detector sites were calculated for each flux shape. (author). 6 tabs., 70 figs., 4 refs.

  2. High Flux Isotope Reactor (HFIR)

    Federal Laboratory Consortium — The HFIR at Oak Ridge National Laboratory is a light-water cooled and moderated reactor that is the United States’ highest flux reactor-based neutron source. HFIR...

  3. Flux networks in metabolic graphs

    Warren, P B; Queiros, S M Duarte; Jones, J L

    2009-01-01

    A metabolic model can be represented as a bipartite graph comprising linked reaction and metabolite nodes. Here it is shown how a network of conserved fluxes can be assigned to the edges of such a graph by combining the reaction fluxes with a conserved metabolite property such as molecular weight. A similar flux network can be constructed by combining the primal and dual solutions to the linear programming problem that typically arises in constraint-based modelling. Such constructions may help with the visualization of flux distributions in complex metabolic networks. The analysis also explains the strong correlation observed between metabolite shadow prices (the dual linear programming variables) and conserved metabolite properties. The methods were applied to recent metabolic models for Escherichia coli, Saccharomyces cerevisiae and Methanosarcina barkeri. Detailed results are reported for E. coli; similar results were found for other organisms

  4. Flux pinning property in a single crystal NdBa2Cu3Oy superconductor

    Hasan, M.N.; Kurokawa, T.; Kiuchi, M.; Otabe, E.S.; Matsushita, T.; Chikumoto, N.; Machi, T.; Muralidhar, M.; Murakami, M.

    2005-01-01

    The critical current density J c and the apparent pinning potential U 0 * in a single crystal NdBa 2 Cu 3 O y superconductor which shows a broad peak effect are investigated by measuring a DC magnetization and its relaxation. The field-induced pinning mechanism does not explain the temperature dependence of peak field B p and dip field B d . The experimental results of J c and U 0 * are compared with the theoretical analysis based on the flux creep-flow model, taking the distribution of the flux pinning strength into account. The number of flux lines in the flux bundle (g 2 ), the most probable value of pinning strength (A m ) and distribution width (σ 2 ) are determined so that a good fit is obtained between the experimental and theoretical results. The behavior of these parameters is discussed in correspondence to the disorder transition of flux lines

  5. Boundary fluxes for nonlocal diffusion

    Cortazar, Carmen; Elgueta, Manuel; Rossi, Julio D.; Wolanski, Noemi

    We study a nonlocal diffusion operator in a bounded smooth domain prescribing the flux through the boundary. This problem may be seen as a generalization of the usual Neumann problem for the heat equation. First, we prove existence, uniqueness and a comparison principle. Next, we study the behavior of solutions for some prescribed boundary data including blowing up ones. Finally, we look at a nonlinear flux boundary condition.

  6. Energy flux of hot atoms

    Wotzak, G.P.; Kostin, M.D.

    1976-01-01

    The process in which hot atoms collide with thermal atoms of a gas, transfer kinetic energy to them, and produce additional hot atoms is investigated. A stochastic method is used to obtain numerical results for the spatial and time dependent energy flux of hot atoms in a gas. The results indicate that in hot atom systems a front followed by an intense energy flux of hot atoms may develop

  7. Neonatal Cytokine Profile in the Airway Mucosal Lining Fluid Is Skewed by Maternal Atopy

    Folsgaard, Nilofar V.; Chawes, Bo L.; Rasmussen, Morten A.

    2012-01-01

    on the cytokines and chemokines in the upper airway mucosal lining fluid of healthy neonates. Objectives: To study parental atopic imprinting on the cytokines and chemokines in the upper airway mucosal lining fluid of healthy neonates. Methods: Eighteen cytokines and chemokines were quantified in nasal mucosal...

  8. Flux tubes at finite temperature

    Cea, Paolo [INFN, Sezione di Bari,Via G. Amendola 173, I-70126 Bari (Italy); Dipartimento di Fisica dell’Università di Bari,Via G. Amendola 173, I-70126 Bari (Italy); Cosmai, Leonardo [INFN, Sezione di Bari,Via G. Amendola 173, I-70126 Bari (Italy); Cuteri, Francesca; Papa, Alessandro [Dipartimento di Fisica, Università della Calabria & INFN-Cosenza,Ponte Bucci, cubo 31C, I-87036 Rende (Cosenza) (Italy)

    2016-06-07

    The chromoelectric field generated by a static quark-antiquark pair, with its peculiar tube-like shape, can be nicely described, at zero temperature, within the dual superconductor scenario for the QCD confining vacuum. In this work we investigate, by lattice Monte Carlo simulations of the SU(3) pure gauge theory, the fate of chromoelectric flux tubes across the deconfinement transition. We find that, if the distance between the static sources is kept fixed at about 0.76 fm ≃1.6/√σ and the temperature is increased towards and above the deconfinement temperature T{sub c}, the amplitude of the field inside the flux tube gets smaller, while the shape of the flux tube does not vary appreciably across deconfinement. This scenario with flux-tube “evaporation” above T{sub c} has no correspondence in ordinary (type-II) superconductivity, where instead the transition to the phase with normal conductivity is characterized by a divergent fattening of flux tubes as the transition temperature is approached from below. We present also some evidence about the existence of flux-tube structures in the magnetic sector of the theory in the deconfined phase.

  9. P fluxes and exotic branes

    Lombardo, Davide M. [Dipartimento di Fisica, Università di Roma “La Sapienza”,Piazzale Aldo Moro 2, 00185 Roma (Italy); Riccioni, Fabio [INFN - Sezione di Roma, Dipartimento di Fisica, Università di Roma “La Sapienza”,Piazzale Aldo Moro 2, 00185 Roma (Italy); Risoli, Stefano [Dipartimento di Fisica, Università di Roma “La Sapienza”,Piazzale Aldo Moro 2, 00185 Roma (Italy); INFN - Sezione di Roma, Dipartimento di Fisica, Università di Roma “La Sapienza”,Piazzale Aldo Moro 2, 00185 Roma (Italy)

    2016-12-21

    We consider the N=1 superpotential generated in type-II orientifold models by non-geometric fluxes. In particular, we focus on the family of P fluxes, that are related by T-duality transformations to the S-dual of the Q flux. We determine the general rule that transforms a given flux in this family under a single T-duality transformation. This rule allows to derive a complete expression for the superpotential for both the IIA and the IIB theory for the particular case of a T{sup 6}/[ℤ{sub 2}×ℤ{sub 2}] orientifold. We then consider how these fluxes modify the generalised Bianchi identities. In particular, we derive a fully consistent set of quadratic constraints coming from the NS-NS Bianchi identities. On the other hand, the P flux Bianchi identities induce tadpoles, and we determine a set of exotic branes that can be consistently included in order to cancel them. This is achieved by determining a universal transformation rule under T-duality satisfied by all the branes in string theory.

  10. P fluxes and exotic branes

    Lombardo, Davide M.; Riccioni, Fabio; Risoli, Stefano

    2016-01-01

    We consider the N=1 superpotential generated in type-II orientifold models by non-geometric fluxes. In particular, we focus on the family of P fluxes, that are related by T-duality transformations to the S-dual of the Q flux. We determine the general rule that transforms a given flux in this family under a single T-duality transformation. This rule allows to derive a complete expression for the superpotential for both the IIA and the IIB theory for the particular case of a T 6 /[ℤ 2 ×ℤ 2 ] orientifold. We then consider how these fluxes modify the generalised Bianchi identities. In particular, we derive a fully consistent set of quadratic constraints coming from the NS-NS Bianchi identities. On the other hand, the P flux Bianchi identities induce tadpoles, and we determine a set of exotic branes that can be consistently included in order to cancel them. This is achieved by determining a universal transformation rule under T-duality satisfied by all the branes in string theory.

  11. Separation of magnetic field lines

    Boozer, Allen H.

    2012-01-01

    The field lines of magnetic fields that depend on three spatial coordinates are shown to have a fundamentally different behavior from those that depend on two coordinates. Unlike two-coordinate cases, a flux tube in a magnetic field that depends on all three spatial coordinates that has a circular cross section at one location along the tube characteristically has a highly distorted cross section at other locations. In an ideal evolution of a magnetic field, the current densities typically increase. Crudely stated, if the current densities increase by a factor σ, the ratio of the long to the short distance across a cross section of a flux tube characteristically increases by e 2σ , and the ratio of the longer distance to the initial radius increases as e σ . Electron inertia prevents a plasma from isolating two magnetic field structures on a distance scale shorter than c/ω pe , which is about 10 cm in the solar corona, and reconnection must be triggered if σ becomes sufficiently large. The radius of the sun, R ⊙ =7×10 10 cm is about e 23 times larger, so when σ≳23, two lines separated by c/ω pe at one location can be separated by the full scale of any magnetic structures in the corona at another. The conditions for achieving a large exponentiation, σ, are derived, and the importance of exponentiation is discussed.

  12. Multi-wavelength high-resolution observations of a small-scale emerging magnetic flux event and the chromospheric and coronal response

    Vargas Domínguez, Santiago; Kosovichev, Alexander; Yurchyshyn, Vasyl, E-mail: svargas@bbso.njit.edu [Big Bear Solar Observatory, NJIT, 40386 North Shore Lane, Big Bear City, CA 92314-9672 (United States)

    2014-10-20

    State-of-the-art solar instrumentation is now revealing magnetic activity of the Sun with unprecedented temporal and spatial resolutions. Observations with the 1.6 m aperture New Solar Telescope (NST) of the Big Bear Solar Observatory are making next steps in our understanding of the solar surface structure. Granular-scale magnetic flux emergence and the response of the solar atmosphere are among the key research topics of high-resolution solar physics. As part of a joint observing program with NASA's Interface Region Imaging Spectrograph (IRIS) mission on 2013 August 7, the NST observed active region NOAA 11,810 in the photospheric TiO 7057 Å band with a resolution of pixel size of 0.''034 and chromospheric He I 10830 Å and Hα 6563 Å wavelengths. Complementary data are provided by the Solar Dynamics Observatory (SDO) and Hinode space-based telescopes. The region displayed a group of solar pores, in the vicinity of which we detect a small-scale buoyant horizontal magnetic flux tube causing granular alignments and interacting with the preexisting ambient field in the upper atmospheric layers. Following the expansion of distorted granules at the emergence site, we observed a sudden appearance of an extended surge in the He I 10830 Å data (bandpass of 0.05 Å). The IRIS transition region imaging caught ejection of a hot plasma jet associated with the He I surge. The SDO/HMI data used to study the evolution of the magnetic and Doppler velocity fields reveal emerging magnetic loop-like structures. Hinode/Ca II H and IRIS filtergrams detail the connectivities of the newly emerged magnetic field in the lower solar chromosphere. From these data, we find that the orientation of the emerging magnetic field lines from a twisted flux tube formed an angle of ∼45° with the overlying ambient field. Nevertheless, the interaction of emerging magnetic field lines with the pre-existing overlying field generates high-temperature emission regions and boosts the

  13. Lateral chest radiographic findings in lobar collapse of the left lung : the distance between both upper lobe bronchi

    Chin, G. H.; Sung, D. W.; Yoon, Y.; Kim, H. C.

    1996-01-01

    To evaluate the distance between both upper love bronchi on lateral radiographs and its change in left upper or lower lobe collapse. 144 true lateral radiographs were analyzed on which both upper lobe bronchi were clearly identified. They included 116 normal cases, 11 cases of left upper lobe collapse, 13 of left lower lobe collapse, and 4 cases of left lower lobe lobectomy. Line A was drawn parallel to the vertebral end plate through the upper margin of the lift upper lobe bronchus. Line B was drawn parallel to line A through the upper margin of the right upper love bronchus. The shortest distance between line A and line B was measured as the distance between both upper lobe bronchi. In normal cases, the mean value of the distance was 2.19 cm ± S.D. 0.37 cm on right and on right and 2.16 cm ± S.D. 0.40 cm on left lateral radiographs ; these results were not significantly different(P=0.79). In cases of collapse, the mean value of the distance was 0.43 cm ± S.D. 0.99 cm in upper lobe collapse and 3.56 cm ± S.D. 0.72 cm in lower lobe collapse, results which were significantly different from those of normal cases(p<0.01). In eight cases(73%) of left upper lobe collapse, the distance was less than 1 cm and in 10 cases(77%) of left lower lobe collapse, the distance was more than 3 cm. The distance between both upper lobe bronchi varies markedly in case of lobar collapse. A distance of less than 1 cm suggests collapse of the left upper lobe and a distance more than 3 cm suggests collapse of the left lower lobe

  14. Focusing of cosmic radiation near power lines. A theoretical approach

    Skedsmo, A.; Vistnes, A.I.

    1997-02-01

    The purpose of this work was to determine if, and to what extent, cosmic radiation can be focused by power lines. As an alternative to experimental measurements, a computer program was developed for simulation of particle trajectories. Starting from given initial values, the cosmic particles trajectories through the electromagnetic field surrounding power lines were simulated. Particular efforts have been made to choose initial values which represent the actual physical condition of the cosmic radiation at ground level. The results show an average decrease in the particle flux density in an area below a power line and a corresponding increased flux between 12 m and 45 m on either side of the centre of the power line. The average shift in flux density is, however, extremely small (less than 0.1%) and probably not measurable with existing detector technology. 11 refs., 4 figs., 2 tabs

  15. Reduction of the visual impact of overhead transmission line systems through utilisation of line surge arresters as lightning protection

    Sørensen, Thomas Kjærsgaard; Holbøll, Joachim

    2008-01-01

    with the Technical University of Denmark, on how to lessen the visual impact of 400 kV overhead line transmission systems. In this paper omission of shield wires combined with installation of a suitable number of line surge arresters is investigated as a possible alternative to transmission lines equipped...... with shielding wires thereby reducing tower height, allowing more compact designs of towers thus minimizing the visual environment impact of the lines. Omission of shield wires in the system and instead utilizing a larger number of surge arresters in the (upper) phases of an overhead line without reduction...... will be investigated by transient simulations on a 400 kV line with either shield wires or line surge arresters. These simulations will also be used to estimate number and location of the line surge arresters in the line to ensure a satisfactory performance of the line when omitting shield wires in the tower top...

  16. Formation and dynamics of a solar eruptive flux tube

    Inoue, Satoshi; Kusano, Kanya; Büchner, Jörg; Skála, Jan

    2018-01-01

    Solar eruptions are well-known drivers of extreme space weather, which can greatly disturb the Earth's magnetosphere and ionosphere. The triggering process and initial dynamics of these eruptions are still an area of intense study. Here we perform a magnetohydrodynamic simulation taking into account the observed photospheric magnetic field to reveal the dynamics of a solar eruption in a real magnetic environment. In our simulation, we confirmed that tether-cutting reconnection occurring locally above the polarity inversion line creates a twisted flux tube, which is lifted into a toroidal unstable area where it loses equilibrium, destroying the force-free state, and driving the eruption. Consequently, a more highly twisted flux tube is built up during this initial phase, which can be further accelerated even when it returns to a stable area. We suggest that a nonlinear positive feedback process between the flux tube evolution and reconnection is the key to ensure this extra acceleration.

  17. Coordinates for Representing Radiation Belt Particle Flux

    Roederer, Juan G.; Lejosne, Solène

    2018-02-01

    Fifty years have passed since the parameter "L-star" was introduced in geomagnetically trapped particle dynamics. It is thus timely to review the use of adiabatic theory in present-day studies of the radiation belts, with the intention of helping to prevent common misinterpretations and the frequent confusion between concepts like "distance to the equatorial point of a field line," McIlwain's L-value, and the trapped particle's adiabatic L* parameter. And too often do we miss in the recent literature a proper discussion of the extent to which some observed time and space signatures of particle flux could simply be due to changes in magnetospheric field, especially insofar as off-equatorial particles are concerned. We present a brief review on the history of radiation belt parameterization, some "recipes" on how to compute adiabatic parameters, and we illustrate our points with a real event in which magnetospheric disturbance is shown to adiabatically affect the particle fluxes measured onboard the Van Allen Probes.

  18. Upper plenum dump during reflood in PWR loss-of-coolant accident

    Sudo, Yukio; Griffith, Peter.

    1981-01-01

    Upper plenum dump during reflood in a large break loww-of-coolant accident of PWR is studied with the emergency core coolant injection into the upper plenum in addition to the cold leg. Transient experiments were carried out by injecting water into the upper plenum and the simple analysis based on a one-dimensional model was done using the drift flux model in order to investigate the conditions under which water dump through the core occurs during reflood. The most significant result is an upper plenum dump occurs when the pressure (hydrostatic head) in the upper plenum is greater than that in the lower plenum. Under those circumstances the flow regime isco-current down flow in which the upper plenum is rapidly emptied. On the other hand, when the upper plenum pressure (hydrostatic head) is less than the lower plenum pressure (hydrostatic head), the co-current down flow is not realized but a counter-current flow occurs. With subcooled water injection to the upper plenum, co-current down flow is realized even when the upper plenum hydrostatic head is less than the lower plenum hydrostatic head. The importance of this effect varies according to the magnetude of water subcooling. (author)

  19. Diurnal variability of surface fluxes at an oceanic station in the Bay of Bengal

    Sarma, Y.V.B.; Rao, D.P.

    Diurnal variability of the surface fluxes and ocean heat content was studied using the time-series data on marine surface meteorological parameters and upper ocean temperature collected at an oceanic station in the Bay of Bengal during 1st to 8th...

  20. TRACING THE LOWEST PROPELLER LINE IN MAGELLANIC HIGH-MASS X-RAY BINARIES

    Christodoulou, Dimitris M.; Laycock, Silas G. T.; Yang, Jun; Fingerman, Samuel, E-mail: dimitris_christodoulou@uml.edu, E-mail: silas_laycock@uml.edu, E-mail: jun_yang@uml.edu, E-mail: fingerman.samuel@gmail.com [Lowell Center for Space Science and Technology, 600 Suffolk Street, Lowell, MA 01854 (United States)

    2016-09-20

    We have combined the published observations of high-mass X-ray binary (HMXB) pulsars in the Magellanic Clouds with a new processing of the complete archival data sets from the XMM-Newton and Chandra observatories in an attempt to trace the lowest propeller line below which accretion to polar caps is inhibited by the centrifugal force and the pulsations from the most weakly magnetized pulsars cease. Previously published data reveal that some of the faster-spinning pulsars with spin periods of P {sub S} < 12 s, detected at relatively low X-ray luminosities L {sub X} , appear to define such a line in the P {sub S} – L {sub X} diagram, characterized by a magnetic moment of μ = 3 × 10{sup 29} G cm{sup 3}. This value implies the presence of surface magnetic fields of B ≥ 3 × 10{sup 11} G in the compact objects of this class. Only a few quiescent HMXBs are found below the propeller line: LXP4.40 and SXP4.78, for which XMM-Newton and Chandra null detections respectively placed firm upper limits on their X-ray fluxes in deep quiescence; and A0538-66, for which many sub-Eddington detections have never measured any pulsations. On the other hand, the data from the XMM-Newton and Chandra archives show clearly that, during routine observation cycles, several sources have been detected below the propeller line in extremely faint, nonpulsating states that can be understood as the result of weak magnetospheric emission when accretion to the poles is centrifugally stalled or severely diminished. We also pay attention to the anomalous X-ray pulsar CXOU J010043.1-721134 that was reported in HMXB surveys. Its pulsations and locations near and above the propeller line indicate that this pulsar could be accreting from a fossil disk.

  1. Magnitude corrections for attenuation in the upper mantle

    Anon.

    1978-01-01

    Since 1969, a consistent discrepancy in seismic magnitudes of nuclear detonations at NTS compared with magnitudes of detonations elsewhere in the world has been observed. This discrepancy can be explained in terms of a relatively high seismic attenuation for compressional waves in the upper mantle beneath the NTS and in certain other locations. A correction has been developed for this attenuation based on a relationship between the velocity of compressional waves at the top of the earth's mantle (just beneath the Mohorovicic discontinuity) and the seismic attenuation further down in the upper mantle. Our new definition of body-wave magnitude includes corrections for attenuation in the upper mantle at both ends of the teleseismic body-wave path. These corrections bring the NTS oservations into line with measurements of foreign events, and enable one to make more reliable estimates of yields of underground nuclear explosions, wherever the explosion occurs

  2. Flux lattice melting in high-Tc superconductors

    Houghton, A.; Pelcovits, R.A.; Sudbo, A.

    1989-01-01

    We derive the wave-vector-dependent elastic moduli for a flux line lattice in compounds with underlying tetragonal crystalline symmetry. We find that it is essential to retain wave-vector dependence of the moduli when dealing with compounds where κ is large, as it is in the high-T c materials. We use our results to establish a Lindemann criterion for flux lattice melting, which we then compare with experimental data on two materials, and find excellent agreement. The melting curves are suppressed well below the mean-field superconducting-normal transition line and are linear in temperature over a wide range of magnetic fields. The point H=0, T=T c is approached as 1-T/T c ∼H 1/2 . The degree of suppression of the melting curves among the different compounds is accounted for in the main by differences in mass anisotropy

  3. Semi-analytic flux formulas for shielding calculations

    Wallace, O.J.

    1976-06-01

    A special coordinate system based on the work of H. Ono and A. Tsuro has been used to derive exact semi-analytic formulas for the flux from cylindrical, spherical, toroidal, rectangular, annular and truncated cone volume sources; from cylindrical, spherical, truncated cone, disk and rectangular surface sources; and from curved and tilted line sources. In most of the cases where the source is curved, shields of the same curvature are allowed in addition to the standard slab shields; cylindrical shields are also allowed in the rectangular volume source flux formula. An especially complete treatment of a cylindrical volume source is given, in which dose points may be arbitrarily located both within and outside the source, and a finite cylindrical shield may be considered. Detector points may also be specified as lying within spherical and annular source volumes. The integral functions encountered in these formulas require at most two-dimensional numeric integration in order to evaluate the flux values. The classic flux formulas involving only slab shields and slab, disk, line, sphere and truncated cone sources become some of the many special cases which are given in addition to the more general formulas mentioned above

  4. Upper limit on the inner radiation belt MeV electron intensity

    Li, X; Selesnick, RS; Baker, DN; Jaynes, AN; Kanekal, SG; Schiller, Q; Blum, L; Fennell, J; Blake, JB

    2015-01-01

    No instruments in the inner radiation belt are immune from the unforgiving penetration of the highly energetic protons (tens of MeV to GeV). The inner belt proton flux level, however, is relatively stable; thus, for any given instrument, the proton contamination often leads to a certain background noise. Measurements from the Relativistic Electron and Proton Telescope integrated little experiment on board Colorado Student Space Weather Experiment CubeSat, in a low Earth orbit, clearly demonstrate that there exist sub-MeV electrons in the inner belt because their flux level is orders of magnitude higher than the background, while higher-energy electron (>1.6 MeV) measurements cannot be distinguished from the background. Detailed analysis of high-quality measurements from the Relativistic Electron and Proton Telescope on board Van Allen Probes, in a geo-transfer-like orbit, provides, for the first time, quantified upper limits on MeV electron fluxes in various energy ranges in the inner belt. These upper limits are rather different from flux levels in the AE8 and AE9 models, which were developed based on older data sources. For 1.7, 2.5, and 3.3 MeV electrons, the upper limits are about 1 order of magnitude lower than predicted model fluxes. The implication of this difference is profound in that unless there are extreme solar wind conditions, which have not happened yet since the launch of Van Allen Probes, significant enhancements of MeV electrons do not occur in the inner belt even though such enhancements are commonly seen in the outer belt. Key Points Quantified upper limit of MeV electrons in the inner belt Actual MeV electron intensity likely much lower than the upper limit More detailed understanding of relativistic electrons in the magnetosphere PMID:26167446

  5. SMM observations of gamma-ray transients. 3: A search for a broadened, redshifted positron annihilation line from the direction of the Galactic center

    Harris, Michael J.; Share, Gerald H.; Leising, Mark D.

    1994-01-01

    We have searched for 1980-1988 Solar Maximum Mission gamma-ray spectrometer data for transient emission on timescales from hours to approximately 12 days of broad gamma-ray lines at energies approximately 400 keV, which were reported by the High Energy Astronomy Observatory (HEAO) 1 and SIGMA experiments from two sources lying toward the Galactic center. The lines have been interpreted as the product of the annihilation of positrons in pair plasmas surrounding the black hole candidate 1E 1740.7-2942 and the X-ray binary 1H 1822-371. Our results from a combined exposure of approximately 1.5 x 10(exp 7)s provide no convincing evidence for transient emission of this line on any timescale between approximately 9 hr and approximately 1 yr. Our 3 sigma upper limits on the line flux during approximately 12 day intervals are characteristically 4.8 x 10(exp -3) photon/sq cm/s, while for approximately 1 day intervals our 3 sigma upper limits are characteristically 4.9 x 10(exp -3) photon/sq cm/s. These results imply a duty cycle of less than 1.3% for the transient line measured from 1H 1822-371 during a approximately 3 week interval in 1977 by HEAO 1, and a duty cycle of less than or = 0.8% for the transient line detected in 1990 and 1992 from 1E 1740.7-2942 on approximately 1 day timescales by SIGMA.

  6. Thermality of the Hawking flux

    Visser, Matt [School of Mathematics, Statistics, and Operations Research,Victoria University of Wellington, PO Box 600, Wellington 6140 (New Zealand)

    2015-07-03

    Is the Hawking flux “thermal”? Unfortunately, the answer to this seemingly innocent question depends on a number of often unstated, but quite crucial, technical assumptions built into modern (mis-)interpretations of the word “thermal”. The original 1850’s notions of thermality — based on classical thermodynamic reasoning applied to idealized “black bodies” or “lamp black surfaces” — when supplemented by specific basic quantum ideas from the early 1900’s, immediately led to the notion of the black-body spectrum, (the Planck-shaped spectrum), but without any specific assumptions or conclusions regarding correlations between the quanta. Many (not all) modern authors (often implicitly and unintentionally) add an extra, quite unnecessary, assumption that there are no correlations in the black-body radiation; but such usage is profoundly ahistorical and dangerously misleading. Specifically, the Hawking flux from an evaporating black hole, (just like the radiation flux from a leaky furnace or a burning lump of coal), is only approximately Planck-shaped over an explicitly bounded range of frequencies. Standard physics (phase space and adiabaticity effects) explicitly bound the frequency range over which the Hawking flux is approximately Planck-shaped from both above and below — the Hawking flux is certainly not exactly Planckian, and there is no compelling physics reason to assume the Hawking photons are uncorrelated.

  7. Thermality of the Hawking flux

    Visser, Matt

    2015-01-01

    Is the Hawking flux “thermal”? Unfortunately, the answer to this seemingly innocent question depends on a number of often unstated, but quite crucial, technical assumptions built into modern (mis-)interpretations of the word “thermal”. The original 1850’s notions of thermality — based on classical thermodynamic reasoning applied to idealized “black bodies” or “lamp black surfaces” — when supplemented by specific basic quantum ideas from the early 1900’s, immediately led to the notion of the black-body spectrum, (the Planck-shaped spectrum), but without any specific assumptions or conclusions regarding correlations between the quanta. Many (not all) modern authors (often implicitly and unintentionally) add an extra, quite unnecessary, assumption that there are no correlations in the black-body radiation; but such usage is profoundly ahistorical and dangerously misleading. Specifically, the Hawking flux from an evaporating black hole, (just like the radiation flux from a leaky furnace or a burning lump of coal), is only approximately Planck-shaped over an explicitly bounded range of frequencies. Standard physics (phase space and adiabaticity effects) explicitly bound the frequency range over which the Hawking flux is approximately Planck-shaped from both above and below — the Hawking flux is certainly not exactly Planckian, and there is no compelling physics reason to assume the Hawking photons are uncorrelated.

  8. Physics of magnetic flux tubes

    Ryutova, Margarita

    2015-01-01

    This book is the first account of the physics of magnetic flux tubes from their fundamental properties to collective phenomena in an ensembles of flux tubes. The physics of magnetic flux tubes is absolutely vital for understanding fundamental physical processes in the solar atmosphere shaped and governed by magnetic fields. High-resolution and high cadence observations from recent space and  ground-based instruments taken simultaneously at different heights and temperatures not only show the ubiquity of filamentary structure formation but also allow to study how various events are interconnected by system of magnetic flux tubes. The book covers both theory and observations. Theoretical models presented in analytical and phenomenological forms are tailored for practical applications. These are welded with state-of-the-art observations from early decisive ones to the most recent data that open a new phase-space for exploring the Sun and sun-like stars. Concept of magnetic flux tubes is central to various magn...

  9. Spectropolarimetric Evidence for a Siphon Flow along an Emerging Magnetic Flux Tube

    Requerey, Iker S.; Cobo, B. Ruiz [Instituto de Astrofísica de Canarias, Vía Láctea s/n, E-38205 La Laguna, Tenerife (Spain); Iniesta, J. C. Del Toro; Suárez, D. Orozco [Instituto de Astrofísica de Andalucía (CSIC), Apdo. de Correos 3004, E-18080 Granada (Spain); Rodríguez, J. Blanco [Grupo de Astronomía y Ciencias del Espacio, Universidad de Valencia, E-46980 Paterna, Valencia (Spain); Solanki, S. K.; Barthol, P.; Gandorfer, A.; Gizon, L.; Hirzberger, J.; Riethmüller, T. L.; Noort, M. van [Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, D-37077 Göttingen (Germany); Schmidt, W. [Kiepenheuer-Institut für Sonnenphysik, Schöneckstr. 6, D-79104 Freiburg (Germany); Pillet, V. Martínez [National Solar Observatory, 3665 Discovery Drive, Boulder, CO 80303 (United States); Knölker, M., E-mail: iker@iac.es [High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000 (United States)

    2017-03-01

    We study the dynamics and topology of an emerging magnetic flux concentration using high spatial resolution spectropolarimetric data acquired with the Imaging Magnetograph eXperiment on board the sunrise balloon-borne solar observatory. We obtain the full vector magnetic field and the line of sight (LOS) velocity through inversions of the Fe i line at 525.02 nm with the SPINOR code. The derived vector magnetic field is used to trace magnetic field lines. Two magnetic flux concentrations with different polarities and LOS velocities are found to be connected by a group of arch-shaped magnetic field lines. The positive polarity footpoint is weaker (1100 G) and displays an upflow, while the negative polarity footpoint is stronger (2200 G) and shows a downflow. This configuration is naturally interpreted as a siphon flow along an arched magnetic flux tube.

  10. Vertical motions in an intense magnetic flux tube. Pt. 4

    Webb, A.R.; Roberts, B.

    1980-01-01

    Radiative damping of waves is important in the upper photosphere. It is thus of interest to examine the effect of radiative relaxation on the propagation of waves in an intense magnetic flux tube embedded in a uniform atmosphere. Assuming Newton's law of cooling, it is shown that the radiative energy loss leads to wave damping. Both the damping per wavelength and the damping per period reach maximum value when the sound and radiative timescales are comparable. The stronger the magnetic field, the greater is the damping. (orig.)

  11. Upper atmosphere research at INPE

    Clemesha, B.R.

    1984-01-01

    Upper atmosphere research at INPE is mainly concerned with the chemistry and dynamics of the stratosphere, upper mesosphere and lower thermosphere, and the middle thermosphere. Experimental work includes lidar observations of the stratospheric aerosol, measurements of stratospheric ozone by Dobson spectrophotometers and by balloon and rocket-borne sondes, lidar measurements of atmospheric sodium, and photometric observations of O, O 2 , OH and Na emissions, including interferrometric measurements of the OI6300 emission for the purpose of determing thermospheric winds and temperature. The airglow observations also include measurements of a number of emissions produced by the precipitation of energetic neutral particles generated by charge exchange in the ring current. Some recent results of INPE's upper atmosphere program are presented. (Author) [pt

  12. Prediction of radiant heat flux from horizontal propane jet fire

    Zhou, Kuibin; Liu, Jiaoyan; Jiang, Juncheng

    2016-01-01

    Highlights: • Line source model for the radiant heat flux from horizontal jet fire is proposed. • A review on the difference between horizontal and vertical jet fires is conducted. • Effects of lift-off distance and flame shape are discussed for the line source model. • Line source model gives encouraging results relative to the validity of model system. - Abstract: Jet fires are often reported to occur in process industry with lots of hazardous heat energy released. A line source model describing the flame emissive power and subsequent heat flux radiated from a horizontal propane jet fire is evaluated through a testing against experimental fire data and comparison against other models. By a review on the jet flame behavior, the correlations of the lift-off distance, flame length and radiative fraction are proposed to close the line source model in theory. It is found that the fuel jet direction holds a considerable effect on the flame behavior by comparison between horizontal and vertical jet fires. Results indicate that the lift-off distance and the flame shape influence the model prediction to some extent. Comparison of model predictions against data collected in the near field and predictions from the point source model and multipoint source model gives encouraging results relative to the validity of model system.

  13. INTERPLANETARY MAGNETIC FLUX DEPLETION DURING PROTRACTED SOLAR MINIMA

    Connick, David E.; Smith, Charles W.; Schwadron, Nathan A.

    2011-01-01

    We examine near-Earth solar wind observations as assembled within the Omni data set over the past 15 years that constitute the latest solar cycle. We show that the interplanetary magnetic field continues to be depleted at low latitudes throughout the protracted solar minimum reaching levels below previously predicted minima. We obtain a rate of flux removal resulting in magnetic field reduction by 0.5 nT yr -1 at 1 AU when averaged over the years 2005-2009 that reduces to 0.3 nT yr -1 for 2007-2009. We show that the flux removal operates on field lines that follow the nominal Parker spiral orientation predicted for open field lines and are largely unassociated with recent ejecta. We argue that the field line reduction can only be accomplished by ongoing reconnection of nominally open field lines or very old closed field lines and we contend that these two interpretations are observationally equivalent and indistinguishable.

  14. Peripherally inserted central catheters and upper extremity deep vein thrombosis

    Ong, B.; Gibbs, H.; Catchpole, I.; Hetherington, R.; Harper, J.

    2006-01-01

    The purpose of the study was to determine the incidence and risk factors for venous thrombosis in patients with a peripherally inserted central catheter (PICC). A retrospective study of all upper extremity venous duplex scans was carried out in the Vascular Medicine department from year 2000 to 2002 inclusive. A chart review of positive scans was undertaken to identify possible thrombotic risk factors. Of 317 upper extremity venous duplex scans carried out, 115, or 32%, were positive for upper extremity deep vein thrombosis. Three main risk factors were identified - presence of a central line, malignancy and administration of chemotherapy. PICC were the most common central line present. Symptomatic thrombosis occurred in 7% of PICC inserted for chemotherapy compared with 1% of PICC inserted for other reasons. Ten per cent of the patients receiving chemotherapy through a PICC developed a thrombosis. The post-thrombotic syndrome was infrequent following upper extremity deep vein thrombosis. Patients receiving chemotherapy through a PICC are at increased risk of thrombosis. There may be a role for prophylactic low-dose anticoagulation in these high-risk patients

  15. Flux driven turbulence in tokamaks

    Garbet, X.; Ghendrih, P.; Ottaviani, M.; Sarazin, Y.; Beyer, P.; Benkadda, S.; Waltz, R.E.

    1999-01-01

    This work deals with tokamak plasma turbulence in the case where fluxes are fixed and profiles are allowed to fluctuate. These systems are intermittent. In particular, radially propagating fronts, are usually observed over a broad range of time and spatial scales. The existence of these fronts provide a way to understand the fast transport events sometimes observed in tokamaks. It is also shown that the confinement scaling law can still be of the gyroBohm type in spite of these large scale transport events. Some departure from the gyroBohm prediction is observed at low flux, i.e. when the gradients are close to the instability threshold. Finally, it is found that the diffusivity is not the same for a turbulence calculated at fixed flux than at fixed temperature gradient, with the same time averaged profile. (author)

  16. Methane flux from boreal peatlands

    Crill, P.; Bartlett, K.; Roulet, N.

    1992-01-01

    The peatlands in the boreal zone (roughly 45 deg - 60 degN) store a significant reservoir of carbon, much of which is potentially available for exchange with the atmosphere. The anaerobic conditions that cause these soils to accumulate carbon also makes wet, boreal peatlands significant sources of methane to the global troposphere. It is estimated that boreal wetlands contribute approximately 19.5 Tg methane per year. The data available on the magnitude of boreal methane emissions have rapidly accumulated in the past twenty years. This paper offers a short review of the flux measured (with range roughly 1 - 2000 mg methane/m2d), considers environmental controls of the flux and briefly discusses how climate change might affect future fluxes

  17. Wide range neutron flux monitor

    Endo, Yorimasa; Fukushima, Toshiki.

    1983-01-01

    Purpose: To provide a wide range neutron-flux monitor adapted such that the flux monitoring function and alarming function can automatically by shifted from pulse counting system to cambel method system. Constitution: A wide range neutron-flux monitor comprises (la) pulse counting system and (lb) cambel-method system for inputting detection signals from neutron detectors and separating them into signals for the pulse measuring system and the cambel measuring system, (2) overlap detection and calculation circuit for detecting the existence of the overlap of two output signals from the (la) and (lb) systems, and (3) trip circuit for judging the abnormal state of neutron detectors upon input of the detection signals. (Seki, T.)

  18. High heat flux facility GLADIS

    Greuner, H.; Boeswirth, B.; Boscary, J.; McNeely, P.

    2007-01-01

    The new ion beam facility GLADIS started the operation at IPP Garching. The facility is equipped with two individual 1.1 MW power ion sources for testing actively cooled plasma facing components under high heat fluxes. Each ion source generates heat loads between 3 and 55 MW/m 2 with a beam diameter of 70 mm at the target position. These parameters allow effective testing from probes to large components up to 2 m length. The high heat flux allows the target to be installed inclined to the beam and thus increases the heated surface length up to 200 mm for a heat flux of 15 MW/m 2 in the standard operating regime. Thus the facility has the potential capability for testing of full scale ITER divertor targets. Heat load tests on the WENDELSTEIN 7-X pre-series divertor targets have been successfully started. These tests will validate the design and manufacturing for the production of 950 elements

  19. Heat flux driven ion turbulence

    Garbet, X.

    1998-01-01

    This work is an analysis of an ion turbulence in a tokamak in the case where the thermal flux is fixed and the temperature profile is allowed to fluctuate. The system exhibits some features of Self-Organized Critical systems. In particular, avalanches are observed. Also the frequency spectrum of the thermal flux exhibits a structure similar to the one of a sand pile automaton, including a 1/f behavior. However, the time average temperature profile is found to be supercritical, i.e. the temperature gradient stays above the critical value. Moreover, the heat diffusivity is lower for a turbulence calculated at fixed flux than a fixed temperature gradient, with the same time average temperature. This behavior is attributed to a stabilizing effect of avalanches. (author)

  20. Spectral estimates of net radiation and soil heat flux

    Daughtry, C.S.T.; Kustas, W.P.; Moran, M.S.; Pinter, P.J. Jr.; Jackson, R.D.; Brown, P.W.; Nichols, W.D.; Gay, L.W.

    1990-01-01

    Conventional methods of measuring surface energy balance are point measurements and represent only a small area. Remote sensing offers a potential means of measuring outgoing fluxes over large areas at the spatial resolution of the sensor. The objective of this study was to estimate net radiation (Rn) and soil heat flux (G) using remotely sensed multispectral data acquired from an aircraft over large agricultural fields. Ground-based instruments measured Rn and G at nine locations along the flight lines. Incoming fluxes were also measured by ground-based instruments. Outgoing fluxes were estimated using remotely sensed data. Remote Rn, estimated as the algebraic sum of incoming and outgoing fluxes, slightly underestimated Rn measured by the ground-based net radiometers. The mean absolute errors for remote Rn minus measured Rn were less than 7%. Remote G, estimated as a function of a spectral vegetation index and remote Rn, slightly overestimated measured G; however, the mean absolute error for remote G was 13%. Some of the differences between measured and remote values of Rn and G are associated with differences in instrument designs and measurement techniques. The root mean square error for available energy (Rn - G) was 12%. Thus, methods using both ground-based and remotely sensed data can provide reliable estimates of the available energy which can be partitioned into sensible and latent heat under non advective conditions

  1. Flux flow and flux creep in thick films of YBCO. [Y-Ba-Cu-O

    Rickets, J.; Vinen, W.F.; Abell, J.S.; Shields, T.C. (Superconductivity Research Group, Univ. of Birmingham (United Kingdom))

    1991-12-01

    The results are described of new experiments designed to study flux creep and flux flow along a single flux percolation path in thick films of YBCO. The flux flow regime is studied by a four-point resistive technique using pulsed currents, and the flux creep regime by observing the rate at which flux enters a superconducting loop in parallel with the resistance that is associated with the flux percolation path. (orig.).

  2. Regularized Biot–Savart Laws for Modeling Magnetic Flux Ropes

    Titov, Viacheslav S.; Downs, Cooper; Mikić, Zoran; Török, Tibor; Linker, Jon A.; Caplan, Ronald M.

    2018-01-01

    Many existing models assume that magnetic flux ropes play a key role in solar flares and coronal mass ejections (CMEs). It is therefore important to develop efficient methods for constructing flux-rope configurations constrained by observed magnetic data and the morphology of the pre-eruptive source region. For this purpose, we have derived and implemented a compact analytical form that represents the magnetic field of a thin flux rope with an axis of arbitrary shape and circular cross-sections. This form implies that the flux rope carries axial current I and axial flux F, so that the respective magnetic field is the curl of the sum of axial and azimuthal vector potentials proportional to I and F, respectively. We expressed the vector potentials in terms of modified Biot–Savart laws, whose kernels are regularized at the axis in such a way that, when the axis is straight, these laws define a cylindrical force-free flux rope with a parabolic profile for the axial current density. For the cases we have studied so far, we determined the shape of the rope axis by following the polarity inversion line of the eruptions’ source region, using observed magnetograms. The height variation along the axis and other flux-rope parameters are estimated by means of potential-field extrapolations. Using this heuristic approach, we were able to construct pre-eruption configurations for the 2009 February 13 and 2011 October 1 CME events. These applications demonstrate the flexibility and efficiency of our new method for energizing pre-eruptive configurations in simulations of CMEs.

  3. The flux database concerted action

    Mitchell, N.G.; Donnelly, C.E.

    1999-01-01

    This paper summarizes the background to the UIR action on the development of a flux database for radionuclide transfer in soil-plant systems. The action is discussed in terms of the objectives, the deliverables and the progress achieved so far by the flux database working group. The paper describes the background to the current initiative and outlines specific features of the database and supporting documentation. Particular emphasis is placed on the proforma used for data entry, on the database help file and on the approach adopted to indicate data quality. Refs. 3 (author)

  4. Testing a new flux rope model using the HELCATS CME catalogue

    Rouillard, Alexis Paul; Lavarra, Michael

    2017-04-01

    We present a magnetically-driven flux rope model that computes the forces acting on a twisted magnetic flux rope from the Sun to 1AU. This model assumes a more realistic flux rope geometry than assumed before by these types of models. The balance of force is computed in an analogous manner to the well-known Chen flux-rope model. The 3-D vector components of the magnetic field measured by a probe flying through the flux rope can be extracted for any flux rope orientation imposed near the Sun. We test this model through a parametric study and a systematic comparison of the model with the HELCATS catalogues (imagery and in situ). We also report on our investigations of other physical mechanisms such as the shift of flux-surfaces associated with the magnetic forces acting to accelerate the flux rope from the lower to upper corona. Finally, we present an evaluation of this model for space-weather predictions. This work was partly funded by the HELCATS project under the FP7 EU contract number 606692.

  5. Vortex line topology during vortex tube reconnection

    McGavin, P.; Pontin, D. I.

    2018-05-01

    This paper addresses reconnection of vortex tubes, with particular focus on the topology of the vortex lines (field lines of the vorticity). This analysis of vortex line topology reveals key features of the reconnection process, such as the generation of many small flux rings, formed when reconnection occurs in multiple locations in the vortex sheet between the tubes. Consideration of three-dimensional reconnection principles leads to a robust measurement of the reconnection rate, even once instabilities break the symmetry. It also allows us to identify internal reconnection of vortex lines within the individual vortex tubes. Finally, the introduction of a third vortex tube is shown to render the vortex reconnection process fully three-dimensional, leading to a fundamental change in the topological structure of the process. An additional interesting feature is the generation of vorticity null points.

  6. Angiography of the upper extremity

    Janevski, B.K.

    1982-01-01

    This thesis provides a description of the technical and medical aspects of arteriography of the upper extremity and an extensive analysis of the angiographic anatomy and pathology of 750 selective studies performed in more than 500 patients. A short historical review is provided of angiography as a whole and of arteriography of the hand in particular. The method of percutaneous transfemoral catheterization of the arteries of the upper extremity and particularly the arteries of the hand is considered, discussing the problems the angiographer encounters frequently, describing the angiographic complications which may occur and emphasizing the measures to keep them to a minimum. The use of vasodilators in hand angiography is discussed. A short description of the embryological patterns persisting in the arteries of the arm is included in order to understand the congenital variations of the arteries of the upper extremity. The angiographic patterns and clinical aspects of the most common pathological processes involving the arteries of the upper extremities are presented. Special attention is paid to the correlation between angiography and pathology. (Auth.)

  7. Approach to upper gastrointestinal bleeding

    Upper gastrointestinal haemorrhage has a variety of causes (Table 1) and is the commonest complication of peptic ulceration and portal hypertension. Peptic ulceration in the duo- denum or stomach and oesophageal varices are the conditions most often responsible for patients who have the potential to present.

  8. Horizontal Diplopia Following Upper Blepharoplasty

    Tomás Ortiz-Basso

    2014-09-01

    Full Text Available Diplopia is an infrequent complication after blepharoplasty. Most of the cases are in its vertical form due to trauma of the extraocular muscles. In this article, we present a case of horizontal diplopia following cosmetic upper blepharoplasty; we review the literature on this unexpected complication and offer some recommendations to avoid it.

  9. Spectral classification of emission-line galaxies

    Veilleux, S.; Osterbrock, D.E.

    1987-01-01

    A revised method of classification of narrow-line active galaxies and H II region-like galaxies is proposed. It involves the line ratios which take full advantage of the physical distinction between the two types of objects and minimize the effects of reddening correction and errors in the flux calibration. Large sets of internally consistent data are used, including new, previously unpublished measurements. Predictions of recent photoionization models by power-law spectra and by hot stars are compared with the observations. The classification is based on the observational data interpreted on the basis of these models. 63 references

  10. The size of the narrow-line-emitting region in the Seyfert 1 galaxy NGC 5548 from emission-line variability

    Peterson, B. M.; Denney, K. D.; De Rosa, G.; Grier, C. J.; Pogge, R. W.; Kochanek, C. S.; Bentz, M. C.; Vestergaard, M.; Kilerci-Eser, E.; G. Galilei, Università di Padova, Vicolo dell'Osservatorio 3 I-35122, Padova (Italy))" data-affiliation=" (Dipartimento di Fisica e Astronomia G. Galilei, Università di Padova, Vicolo dell'Osservatorio 3 I-35122, Padova (Italy))" >Dalla Bontà, E.; G. Galilei, Università di Padova, Vicolo dell'Osservatorio 3 I-35122, Padova (Italy))" data-affiliation=" (Dipartimento di Fisica e Astronomia G. Galilei, Università di Padova, Vicolo dell'Osservatorio 3 I-35122, Padova (Italy))" >Ciroi, S.

    2013-01-01

    The narrow [O III] λλ4959, 5007 emission-line fluxes in the spectrum of the well-studied Seyfert 1 galaxy NGC 5548 are shown to vary with time. From this we show that the narrow-line-emitting region has a radius of only 1-3 pc and is denser (n e ∼ 10 5 cm –3 ) than previously supposed. The [O III] line width is consistent with virial motions at this radius given previous determinations of the black hole mass. Since the [O III] emission-line flux is usually assumed to be constant and is therefore used to calibrate spectroscopic monitoring data, the variability has ramifications for the long-term secular variations of continuum and emission-line fluxes, though it has no effect on shorter-term reverberation studies. We present corrected optical continuum and broad Hβ emission-line light curves for the period 1988-2008.

  11. The size of the narrow-line-emitting region in the Seyfert 1 galaxy NGC 5548 from emission-line variability

    Peterson, B. M.; Denney, K. D.; De Rosa, G.; Grier, C. J.; Pogge, R. W.; Kochanek, C. S. [Department of Astronomy, The Ohio State University, 140 W 18th Avenue, Columbus, OH 43210 (United States); Bentz, M. C. [Department of Physics and Astronomy, Georgia State University, 25 Park Place, Suite 610, Atlanta, GA 30303 (United States); Vestergaard, M.; Kilerci-Eser, E. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Dalla Bontà, E.; Ciroi, S. [Dipartimento di Fisica e Astronomia " G. Galilei," Università di Padova, Vicolo dell' Osservatorio 3 I-35122, Padova (Italy)

    2013-12-20

    The narrow [O III] λλ4959, 5007 emission-line fluxes in the spectrum of the well-studied Seyfert 1 galaxy NGC 5548 are shown to vary with time. From this we show that the narrow-line-emitting region has a radius of only 1-3 pc and is denser (n {sub e} ∼ 10{sup 5} cm{sup –3}) than previously supposed. The [O III] line width is consistent with virial motions at this radius given previous determinations of the black hole mass. Since the [O III] emission-line flux is usually assumed to be constant and is therefore used to calibrate spectroscopic monitoring data, the variability has ramifications for the long-term secular variations of continuum and emission-line fluxes, though it has no effect on shorter-term reverberation studies. We present corrected optical continuum and broad Hβ emission-line light curves for the period 1988-2008.

  12. The Virtual Observatory Service TheoSSA: Establishing a Database of Synthetic Stellar Flux Standards I. NLTE Spectral Analysis of the DA-Type White Dwarf G191-B2B *,**,***,****

    Rauch, T.; Werner, K.; Bohlin, R.; Kruk, J. W.

    2013-01-01

    Hydrogen-rich, DA-type white dwarfs are particularly suited as primary standard stars for flux calibration. State-of-the-art NLTE models consider opacities of species up to trans-iron elements and provide reliable synthetic stellar-atmosphere spectra to compare with observations. Aims. We will establish a database of theoretical spectra of stellar flux standards that are easily accessible via a web interface. Methods. In the framework of the Virtual Observatory, the German Astrophysical Virtual Observatory developed the registered service TheoSSA. It provides easy access to stellar spectral energy distributions (SEDs) and is intended to ingest SEDs calculated by any model-atmosphere code. In case of the DA white dwarf G191-B2B, we demonstrate that the model reproduces not only its overall continuum shape but also the numerous metal lines exhibited in its ultraviolet spectrum. Results. TheoSSA is in operation and contains presently a variety of SEDs for DA-type white dwarfs. It will be extended in the near future and can host SEDs of all primary and secondary flux standards. The spectral analysis of G191-B2B has shown that our hydrostatic models reproduce the observations best at Teff =60 000 +/- 2000K and log g=7.60 +/- 0.05.We newly identified Fe vi, Ni vi, and Zn iv lines. For the first time, we determined the photospheric zinc abundance with a logarithmic mass fraction of -4.89 (7.5 × solar). The abundances of He (upper limit), C, N, O, Al, Si, O, P, S, Fe, Ni, Ge, and Sn were precisely determined. Upper abundance limits of about 10% solar were derived for Ti, Cr, Mn, and Co. Conclusions. The TheoSSA database of theoretical SEDs of stellar flux standards guarantees that the flux calibration of all astronomical data and cross-calibration between different instruments can be based on the same models and SEDs calculated with different model-atmosphere codes and are easy to compare.

  13. Oxyanion flux characterization using passive flux meters: Development and field testing of surfactant-modified granular activated carbon

    Lee, Jimi; Rao, P. S. C.; Poyer, Irene C.; Toole, Robyn M.; Annable, M. D.; Hatfield, K.

    2007-07-01

    We report here on the extension of Passive Flux Meter (PFM) applications for measuring fluxes of oxyanions in groundwater, and present results for laboratory and field studies. Granular activated carbon, with and without impregnated silver (GAC and SI-GAC, respectively), was modified with a cationic surfactant, hexadecyltrimethylammonium (HDTMA), to enhance the anion exchange capacity (AEC). Langmuir isotherm sorption maxima for oxyanions measured in batch experiments were in the following order: perchlorate >> chromate > selenate, consistent with their selectivity. Linear sorption isotherms for several alcohols suggest that surfactant modification of GAC and SI-GAC reduced (˜ 30-45%) sorption of alcohols by GAC. Water and oxyanion fluxes (perchlorate and chromate) measured by deploying PFMs packed with surfactant-modified GAC (SM-GAC) or surfactant-modified, silver-impregnated GAC (SM-SI-GAC) in laboratory flow chambers were in close agreement with the imposed fluxes. The use of SM-SI-GAC as a PFM sorbent was evaluated at a field site with perchlorate contamination of a shallow unconfined aquifer. PFMs packed with SM-SI-GAC were deployed in three existing monitoring wells with a perchlorate concentration range of ˜ 2.5 to 190 mg/L. PFM-measured, depth-averaged, groundwater fluxes ranged from 1.8 to 7.6 cm/day, while depth-averaged perchlorate fluxes varied from 0.22 to 1.7 g/m 2/day. Groundwater and perchlorate flux distributions measured in two PFM deployments closely matched each other. Depth-averaged Darcy fluxes measured with PFMs were in line with an estimate from a borehole dilution test, but much smaller than those based on hydraulic conductivity and head gradients; this is likely due to flow divergence caused by well-screen clogging. Flux-averaged perchlorate concentrations measured with PFM deployments matched concentrations in groundwater samples taken from one well, but not in two other wells, pointing to the need for additional field testing. Use of

  14. Simple models with ALICE fluxes

    Striet, J

    2000-01-01

    We introduce two simple models which feature an Alice electrodynamics phase. In a well defined sense the Alice flux solutions we obtain in these models obey first order equations similar to those of the Nielsen-Olesen fluxtube in the abelian higgs model in the Bogomol'nyi limit. Some numerical solutions are presented as well.

  15. OI Fluorescent Line Contamination in Soft X-Ray Diffuse Background Obtained with Suzaku/XIS

    Sekiya, Norio; Yamasaki, Noriko Y.; Mitsuda, Kazuhisa; Takei, Yoh

    2014-01-01

    The quantitative measurement of OVII line intensity is a powerful method for understanding the soft X-ray diffuse background. By systematically analyzing the OVII line intensity in 145 high-latitude Suzaku/XIS observations, the flux of OI fluorescent line in the XIS spectrum, contaminating the OVII line, is found to have an increasing trend with time especially after 2011. For these observations, the OVII line intensity would be overestimated unless taking into consideration the OI fluorescen...

  16. The truth is out there: measured, calculated and modelled benthic fluxes.

    Pakhomova, Svetlana; Protsenko, Elizaveta

    2016-04-01

    In a modern Earth science there is a great importance of understanding the processes, forming the benthic fluxes as one of element sources or sinks to or from the water body, which affects the elements balance in the water system. There are several ways to assess benthic fluxes and here we try to compare the results obtained by chamber experiments, calculated from porewater distributions and simulated with model. Benthic fluxes of dissolved elements (oxygen, nitrogen species, phosphate, silicate, alkalinity, iron and manganese species) were studied in the Baltic and Black Seas from 2000 to 2005. Fluxes were measured in situ using chamber incubations (Jch) and at the same time sediment cores were collected to assess the porewater distribution at different depths to calculate diffusive fluxes (Jpw). Model study was carried out with benthic-pelagic biogeochemical model BROM (O-N-P-Si-C-S-Mn-Fe redox model). It was applied to simulate biogeochemical structure of the water column and upper sediment and to assess the vertical fluxes (Jmd). By the behaviour at the water-sediment interface all studied elements can be divided into three groups: (1) elements which benthic fluxes are determined by the concentrations gradient only (Si, Mn), (2) elements which fluxes depend on redox conditions in the bottom water (Fe, PO4, NH4), and (3) elements which fluxes are strongly connected with organic matter fate (O2, Alk, NH4). For the first group it was found that measured fluxes are always higher than calculated diffusive fluxes (1.5disadvantages and the main facing us question is - which value should be taken for calculation the balance? This research is funded by VISTA - a basic research program and collaborative partnership between the Norwegian Academy of Science and Letters and Statoil.

  17. Upper canine inclination influences the aesthetics of a smile.

    Bothung, C; Fischer, K; Schiffer, H; Springer, I; Wolfart, S

    2015-02-01

    This current study investigated which angle of canine inclination (angle between canine tooth axis (CA-line) and the line between the lateral canthus and the ipsilateral labial angle (EM-line)) is perceived to be most attractive in a smile. The second objective was to determine whether laymen and dental experts share the same opinion. A Q-sort assessment was performed with 48 posed smile photographs to obtain two models of neutral facial attractiveness. Two sets of images (1 male model set, 1 female model set), each containing seven images with incrementally altered canine and posterior teeth inclinations, were generated. The images were ranked for attractiveness by three groups (61 laymen, 59 orthodontists, 60 dentists). The images with 0° inclination, that is CA-line (maxillary canine axis) parallel to EM-line (the line formed by the lateral canthus and the ipsilateral corner of the mouth) (male model set: 54·4%; female model set: 38·9%), or -5° (inward) inclination (male model set: 20%; female model set: 29·4%) were perceived to be most attractive within each set. Images showing inward canine inclinations were regarded to be more attractive than those with outward inclinations. Dental experts and laymen were in accordance with the aesthetics. Smiles were perceived to be most attractive when the upper canine tooth axis was parallel to the EM-line. In reconstructive or orthodontic therapy, it is thus important to incline canines more inwardly than outwardly. © 2014 John Wiley & Sons Ltd.

  18. Beam line design using G4BeamLine

    Dogan, Arda

    2014-01-01

    In Turkey in Ankara TAEK SANAEM Proton Accelerator Facility (PAF), there is a cyclotron which produces a focused intense 30 MeV proton beam and sends this beam to four different arms, three of which uses this beam to produce pharmaceutical medicine. The remaining one is spared for R&D purposes and the idea was to use these protons coming out from the fourth arm to use space radiation tests, which cannot be done in Turkey at the moment. However, according to SCC 25100 standards which is for 30 MeV protons, the beam coming out of cyclotron is too intense and focused to use for space radiation tests. Therefore, the main aim of my project is to design a beam line which will defocus the beam and reduce the flux so that the space radiation tests can be done according to the standards of SCC 25100.

  19. AA, sandwich line with magnetic horn

    CERN PhotoLab

    1980-01-01

    The magnetic horn, focusing the antiprotons emanating from the target, was affixed to a sandwich line through which the 150 kA pulses were supplied. Expecting to have to change from time to time the fragile horn (inner conductor only 0.7 mm thick), the assembly was designed for quick exchange. At the lower end of the sandwich line we see the connectors for the high-current cables, at the upper end the magnet horn. It has just been lifted from the V-supports which held it aligned downstream of the target. Continue with 8010293.

  20. Comparison of sea surface flux measured by instrumented aircraft and ship during SOFIA and SEMAPHORE experiments

    Durand, Pierre; Dupuis, HéLèNe; Lambert, Dominique; BéNech, Bruno; Druilhet, Aimé; Katsaros, Kristina; Taylor, Peter K.; Weill, Alain

    1998-10-01

    considerable at upper levels in the boundary layer. From arguments linked to the imbalance of the surface energy budget, established during previous campaigns performed over land surfaces with aircraft, we conclude that aircraft heat fluxes are probably also underestimated over the sea.

  1. The role of plumes in mantle helium fluxes

    Kellogg, L.H.; Wasserburg, G.J.

    1990-01-01

    We present a simple model of 3 He and 4 He transport in the mantle using the appropriate rates of mass and species transfer and 4 He production. Previous workers have shown the presence of excess 3 He in hotspots such as Hawaii and Iceland and inferred that these hotspots tap a source with a higher 3 He/ 4 He ratio than the source region of mid-ocean ridge basalts (MORB). Hotspot ocean islands probably originate over upwelling plumes which carry material from the lower mantle to the upper mantle. Melting at hotspots and at mid-ocean ridges degasses the mantle of volatiles such as helium. The upper mantle is outgassed largely of helium due to melting at mid-ocean ridges and hotspots. We postulate that the excess 3 He seen in MORB originates in material that was carried from the lower mantle in plumes but not completely outgassed at hotspots. This helium is incoporated into the depleted upper mantle. Assuming that the upper mantle is in a quasi-steady-state with respect to helium, a simple model balancing 3 He and 4 He fluxes in the upper mantle indicates that the hotspots significantly outgas the lower mantle of 3 He. The concentration of 4 He in the plume source reservoir is 2-3 orders of magnitude lower than the concentration in carbonaceous chondrites. The residence time of helium in the upper mantle depends on the outgassing efficiency at hotspots, since the hotspots may outgas some upper mantle material which has been entrained in the plumes. The residence time of He in the upper mantle is about 1.4x10 9 yr. We conclude that the efficiency of outgassing of He from plumes is high and that the plumes dominate the present 3 He loss to the atmosphere. The 4 He in the less depleted layer of the mantle is not trapped ''primordial'' but is predominantly from in situ decay of U and Th in the depleted layer over ≅ 1.4x10 9 yr. The 4 He in the lower mantle is dominantly from in situ decay of U and Th over 4.4x10 9 yr. (orig./WL)

  2. Upper limit on the diffuse flux of ultrahigh energy tau neutrinos from the Pierre Auger Observatory

    Abraham, J.; Abreu, P.; Aglietta, M.; Aguirre, C.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Alvarez-Muniz, J.; Ambrosio, M.; Anchordoqui, L.; Andringa, S.; Anzalone, A.; Aramo, C.; Argiro, S.; Arisaka, K.; Armengaud, E.; Arneodo, F.; Arqueros, F.; Asch, T.; Asorey, H.; Assis, P.; Atulugama, B. S.; Aublin, J.; Ave, M.; Avila, G.; Baecker, T.; Badagnani, D.; Barbosa, A. F.; Barnhill, D.; Barroso, S. L. C.; Bauleo, P.; Beatty, J. J.; Beau, T.; Becker, B. R.; Becker, K. H.; Bellido, J. A.; BenZvi, S.; Berat, C.; Bergmann, T.; Bernardini, P.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanch-Bigas, O.; Blanco, F.; Blasi, P.; Bleve, C.; Bluemer, H.; Bohacova, M.; Bonifazi, C.; Bonino, R.; Boratav, M.; Brack, J.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Burton, R. E.; Busca, N. G.; Caballero-Mora, K. S.; Cai, B.; Camin, D. V.; Caramete, L.; Caruso, R.; Carvalho, W.; Castellina, A.; Catalano, O.; Cataldi, G.; Cazon, L.; Cester, R.; Chauvin, J.; Chiavassa, A.; Chinellato, J. A.; Chou, A.; Chye, J.; Clark, P. D. J.; Clay, R. W.; Colombo, E.; Conceicao, R.; Connolly, B.; Contreras, F.; Coppens, J.; Cordier, A.; Cotti, U.; Coutu, S.; Covault, C. E.; Creusot, A.; Criss, A.; Cronin, J.; Curutiu, A.; Dagoret-Campagne, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Donato, C.; de Jong, S. J.; De La Vega, G.; de Mello, W. J. M.; de Mello Neto, J. R. T.; DeMitri, I.; de Souza, V.; del Peral, L.; Deligny, O.; Della Selva, A.; Delle Fratte, C.; Dembinski, H.; Di Giulio, C.; Diaz, J. C.; Dobrigkeit, C.; D'Olivo, J. C.; Dornic, D.; Dorofeev, A.; dos Anjos, J. C.; Dova, M. T.; D'Urso, D.; Dutan, I.; DuVernois, M. A.; Engel, R.; Epele, L.; Escobar, C. O.; Etchegoyen, A.; San Luis, P. Facal; Falcke, H.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferrer, F.; Ferry, S.; Fick, B.; Filevich, A.; Filipcic, A.; Fleck, I.; Fonte, R.; Fracchiolla, C. E.; Fulgione, W.; Garcia, B.; Gamez, D. Garcia; Garcia-Pinto, D.; Garrido, X.; Geenen, H.; Gelmini, G.; Gemmeke, H.; Ghia, P. L.; Giller, M.; Glass, H.; Gold, M. S.; Golup, G.; Albarracin, F. Gomez; Berisso, M. Gomez; Herrero, R. Gomez; Goncalves, P.; do Amaral, M. Goncalves; Gonzalez, D.; Gonzalez, J. G.; Gonzalez, M.; Gora, D.; Gorgi, A.; Gouffon, P.; Grassi, V.; Grillo, A. F.; Grunfeld, C.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Gutierrez, J.; Hague, J. D.; Hamilton, J. C.; Hansen, P.; Harari, D.; Harmsma, S.; Harton, J. L.; Haungs, A.; Hauschildt, T.; Healy, M. D.; Hebbeker, T.; Hebrero, G.; Heck, D.; Hojvat, C.; Holmes, V. C.; Homola, P.; Hoerandel, J.; Horneffer, A.; Horvat, M.; Hrabovsky, M.; Huege, T.; Hussain, M.; Iarlori, M.; Insolia, A.; Ionita, F.; Italiano, A.; Kaducak, M.; Kampert, K. H.; Karova, T.; Kegl, B.; Keilhauer, B.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapik, R.; Knapp, J.; Koang, D. -H.; Krieger, A.; Kroemer, O.; Kuempel, D.; Kunka, N.; Kusenko, A.; La Rosa, G.; Lachaud, C.; Lago, B. L.; Lebrun, D.; LeBrun, P.; Lee, J.; de Oliveira, M. A. Leigui; Letessier-Selvon, A.; Leuthold, M.; Lhenry-Yvon, I.; Lopez, R.; Agueera, A. Lopez; Bahilo, J. Lozano; Garcia, R. Luna; Maccarone, M. C.; Macolino, C.; Maldera, S.; Mancarella, G.; Mancenido, M. E.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Maris, I. C.; Falcon, H. R. Marquez; Martello, D.; Martinez, J.; Bravo, O. Martinez; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurizio, D.; Mazur, P. O.; McCauley, T.; McEwen, M.; McNeil, R. R.; Medina, M. C.; Medina-Tanco, G.; Meli, A.; Melo, D.; Menichetti, E.; Menschikov, A.; Meurer, Chr.; Meyhandan, R.; Micheletti, M. I.; Miele, G.; Miller, W.; Mollerach, S.; Monasor, M.; Ragaigne, D. Monnier; Montanet, F.; Morales, B.; Morello, C.; Moreno, J. C.; Morris, C.; Mostafa, M.; Muller, M. A.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Newman-Holmes, C.; Newton, D.; Thi, T. Nguyen; Nierstenhoefer, N.; Nitz, D.; Nosek, D.; Nozka, L.; Oehlschlaeger, J.; Ohnuki, T.; Olinto, A.; Olmos-Gilbaja, V. M.; Ortiz, M.; Ortolani, F.; Ostapchenko, S.; Otero, L.; Pacheco, N.; Selmi-Dei, D. Pakk; Palatka, M.; Pallotta, J.; Parente, G.; Parizot, E.; Parlati, S.; Pastor, S.; Patel, M.; Paul, T.; Pavlidou, V.; Payet, K.; Pech, M.; Pekala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Petrera, S.; Petrinca, P.; Petrov, Y.; Ngoc, Diep Pham; Ngoc, Dong Pham; Thi, T. N. Pham; Pichel, A.; Piegaia, R.; Pierog, T.; Pimenta, M.; Pinto, T.; Pirronello, V.; Pisanti, O.; Platino, M.; Pochon, J.; Privitera, P.; Prouza, M.; Quel, E. J.; Rautenberg, J.; Redondo, A.; Reucroft, S.; Revenu, B.; Rezende, F. A. S.; Ridky, J.; Riggi, S.; Risse, M.; Riviere, C.; Rizi, V.; Roberts, M.; Robledo, C.; Rodriguez, G.; Frias, D. Rodriguez; Martino, J. Rodriguez; Rojo, J. Rodriguez; Rodriguez-Cabo, I.; Ros, G.; Rosado, J.; Roth, M.; Rouille-d'Orfeuil, B.; Roulet, E.; Rovero, A. C.; Salamida, F.; Salazar, H.; Salina, G.; Sanchez, F.; Santander, M.; Santo, C. E.; Santos, E. M.; Sarazin, F.; Sarkar, S.; Sato, R.; Scherini, V.; Schieler, H.; Schmidt, A.; Schmidt, F.; Schmidt, T.; Scholten, O.; Schovanek, P.; Schuessler, F.; Sciutto, S. J.; Scuderi, M.; Segreto, A.; Semikoz, D.; Settimo, M.; Shellard, R. C.; Sidelnik, I.; Siffert, B. B.; Sigl, G.; De Grande, N. Smetniansky; Smialkowski, A.; Smida, R.; Smith, A. G. K.; Smith, B. E.; Snow, G. R.; Sokolsky, P.; Sommers, P.; Sorokin, J.; Spinka, H.; Squartini, R.; Strazzeri, E.; Stutz, A.; Suarez, F.; Suomijaervi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Takahashi, J.; Tamashiro, A.; Tamburro, A.; Tascau, O.; Tcaciuc, R.; Thomas, D.; Ticona, R.; Tiffenberg, J.; Timmermans, C.; Tkaczyk, W.; Peixoto, C. J. Todero; Tome, B.; Tonachini, A.; Torres, I.; Torresi, D.; Travnicek, P.; Tripathi, A.; Tristram, G.; Tscherniakhovski, D.; Tueros, M.; Tunnicliffe, V.; Ulrich, R.; Unger, M.; Urban, M.; Galicia, J. F. Valdes; Valino, I.; Valore, L.; van den Berg, A. M.; van Elewyck, V.; Vazquez, R. A.; Veberic, D.; Veiga, A.; Velarde, A.; Venters, T.; Verzi, V.; Videla, M.; Villasenor, L.; Vorobiov, S.; Voyvodic, L.; Wahlberg, H.; Wainberg, O.; Walker, P.; Warner, D.; Watson, A. A.; Westerhoff, S.; Wieczorek, G.; Wiencke, L.; Wilczynska, B.; Wilczynski, H.; Wileman, C.; Winnick, M. G.; Wu, H.; Wundheiler, B.; Yamamoto, T.; Younk, P.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zech, A.; Zepeda, A.; Ziolkowski, M.

    2008-01-01

    The surface detector array of the Pierre Auger Observatory is sensitive to Earth-skimming tau neutrinos that interact in Earth's crust. Tau leptons from nu(tau) charged-current interactions can emerge and decay in the atmosphere to produce a nearly horizontal shower with a significant

  3. Preconditioning of Antarctic maximum sea-ice extent by upper-ocean stratification on a seasonal timescale

    Su, Zhan

    2017-01-01

    This study uses an observationally constrained and dynamically consistent ocean and sea ice state estimate. The author presents a remarkable agreement between the location of the edge of Antarctic maximum sea ice extent, reached in September, and the narrow transition band for the upper ocean (0–100 m depths) stratification, as early as April to June. To the south of this edge, the upper ocean has high stratification, which forbids convective fluxes to cross through; consequently, the ocean h...

  4. Transport calculations of. gamma. -ray flux density and dose rate about implantable californium-252 sources

    Shapiro, A; Lin, B I [Cincinnati Univ., Ohio (USA). Dept. of Chemical and Nuclear Engineering; Windham, J P; Kereiakes, J G

    1976-07-01

    ..gamma.. flux density and dose rate distributions have been calculated about implantable californium-252 sources for an infinite tissue medium. Point source flux densities as a function of energy and position were obtained from a discrete-ordinates calculation, and the flux densities were multiplied by their corresponding kerma factors and added to obtain point source dose rates. The point dose rates were integrated over the line source to obtain line dose rates. Container attenuation was accounted for by evaluating the point dose rate as a function of platinum thickness. Both primary and secondary flux densities and dose rates are presented. The agreement with an independent Monte Carlo calculation was excellent. The data presented should be useful for the design of new source configurations.

  5. Theoretical investigation of field-line quality in a driven spheromak

    Cohen, R.H.; Cohen, B.I.; Berk, H.L.

    2003-01-01

    Theoretical studies aimed at predicting and diagnosing field-line quality in a spheromak are described. These include nonlinear 3-D MHD simulations, stability studies, analyses of confinement in spheromaks dominated by either open (stochastic) field lines or approximate flux surfaces, and a theory of fast electrons as a probe of field-line length. (author)

  6. Cable line engineering

    Jang, Hak Sin; Kim, Sin Yeong

    1998-02-01

    This book is about cable line engineering. It is comprised of nine chapters, which deals with summary of cable communication such as way, process of cable communication and optical communication, Line constant of transmission on primary constant, reflection and crosstalk, communication cable line of types like flat cable, coaxial cable and loaded cable, Install of communication line with types and facility of aerial line, construction method of communication line facility, Measurement of communication line, Carrier communication of summary, PCM communication with Introduction, regeneration relay system sampling and quantization and Electric communication service and general information network with mobile communication technique and satellite communication system.

  7. The Upper Danube Nature Park

    Dosedla, H.C.

    1997-01-01

    When in 1980 the Upper Danube Nature Park was founded as one of 65 nature sanctuaries in Germany there was great diversity of opinions concerning its intended character. The protected region consisting of a geologically outstanding landscape within central Europe is covering the first 80 km the upper Danube where the young river shortly after it's source in the Black Forest is breaking through the narrow canyons of the Jurassic rock plateau of the so-called Suebian Alps and also locates the subterranean passage where the stream is submerging from the surface for nearly ten miles. Since the purpose of nature preservation according to German las is closely combined with the rather contradicting aim of offering an attractive recreation area thus facing the immense impacts of modern mass tourism there are numerous problems which in the course of years have resulted in an intricate patterns of subtle management methods coping with the growing awareness of the ecological balance. (author)

  8. Flux creep in Bi2Sr2CaCu2O8 epitaxial films

    Zeldov, E.; Amer, N.M.; Koren, G.; Gupta, A.

    1990-01-01

    We incorporate the experimentally deduced flux line potential well structure into the flux creep model. Application of this approach to the resistive transition in Bi 2 Sr 2 CaCu 2 O 8 epitaxial films explains the power law voltage-current characteristics and the nonlinear current dependence of the activation energy. The results cannot be accounted for by a transition into a superconducting vortex-glass phase

  9. Upper limit of peak area

    Helene, O.A.M.

    1982-08-01

    The determination of the upper limit of peak area in a multi-channel spectra, with a known significance level is discussed. This problem is specially important when the peak area is masked by the background statistical fluctuations. The problem is exactly solved and, thus, the results are valid in experiments with small number of events. The results are submitted to a Monte Carlo test and applied to the 92 Nb beta decay. (Author) [pt

  10. Magnetic flux density in the heliosphere through several solar cycles

    Erdős, G. [Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Balogh, A., E-mail: erdos.geza@wigner.mta.hu [The Blackett Laboratory, Imperial College London, London SW7 2BZ (United Kingdom)

    2014-01-20

    We studied the magnetic flux density carried by solar wind to various locations in the heliosphere, covering a heliospheric distance range of 0.3-5.4 AU and a heliolatitudinal range from 80° south to 80° north. Distributions of the radial component of the magnetic field, B{sub R} , were determined over long intervals from the Helios, ACE, STEREO, and Ulysses missions, as well as from using the 1 AU OMNI data set. We show that at larger distances from the Sun, the fluctuations of the magnetic field around the average Parker field line distort the distribution of B{sub R} to such an extent that the determination of the unsigned, open solar magnetic flux density from the average (|B{sub R} |) is no longer justified. We analyze in detail two methods for reducing the effect of fluctuations. The two methods are tested using magnetic field and plasma velocity measurements in the OMNI database and in the Ulysses observations, normalized to 1 AU. It is shown that without such corrections for the fluctuations, the magnetic flux density measured by Ulysses around the aphelion phase of the orbit is significantly overestimated. However, the matching between the in-ecliptic magnetic flux density at 1 AU (OMNI data) and the off-ecliptic, more distant, normalized flux density by Ulysses is remarkably good if corrections are made for the fluctuations using either method. The main finding of the analysis is that the magnetic flux density in the heliosphere is fairly uniform, with no significant variations having been observed either in heliocentric distance or heliographic latitude.

  11. Energy flux to the TEXTOR limiters during disruptions

    Finken, K.H.; Baek, W.Y.; Dippel, K.H.; Boedo, J.A.; Gray, D.S.

    1992-01-01

    Rapidly changing heat fluxes deposited on the limiter blades are observed during disruptions by infrared (IR) scanners. These scanners are a suitable tool for the analysis of these heat fluxes because they provide both spatial and temporal information with sufficient resolution. Several new features of the power flux to the plasma facing surfaces during a disruption have been found. The disruptive heat flux occurs on three different time-scales. The fastest ones are for heat bursts with a duration of ≤0.1 ms; several of these bursts form a thermal quench of about one millisecond duration, and some of these thermal quenches are found to occur during the current decay phase. Power flux densities of the order of 50 MW/m 2 have been observed during a burst. The spatial extent of the area on which this power is deposited during a burst is larger than or equal to the size of half an ALT-II blade, i.e. about 1 m in the toroidal direction. Simultaneous measurements with two cameras show that the correlation length of a single burst is smaller than half the toroidal circumference, probably of the order of half a blade or a full blade length. This is consistent with plasma islands of low mode number. The typical heat deposition patterns at the limiter blades for normal discharges are preserved during a disruption. The magnetic structure near the plasma surface can therefore not be destroyed completely during the thermal quench. The power flux follows the field lines. However, the power e-folding length is about a factor of two to three times larger than under normal discharge conditions. (author). 27 refs, 9 figs

  12. Technology improves upper extremity rehabilitation.

    Kowalczewski, Jan; Prochazka, Arthur

    2011-01-01

    Stroke survivors with hemiparesis and spinal cord injury (SCI) survivors with tetraplegia find it difficult or impossible to perform many activities of daily life. There is growing evidence that intensive exercise therapy, especially when supplemented with functional electrical stimulation (FES), can improve upper extremity function, but delivering the treatment can be costly, particularly after recipients leave rehabilitation facilities. Recently, there has been a growing level of interest among researchers and healthcare policymakers to deliver upper extremity treatments to people in their homes using in-home teletherapy (IHT). The few studies that have been carried out so far have encountered a variety of logistical and technical problems, not least the difficulty of conducting properly controlled and blinded protocols that satisfy the requirements of high-level evidence-based research. In most cases, the equipment and communications technology were not designed for individuals with upper extremity disability. It is clear that exercise therapy combined with interventions such as FES, supervised over the Internet, will soon be adopted worldwide in one form or another. Therefore it is timely that researchers, clinicians, and healthcare planners interested in assessing IHT be aware of the pros and cons of the new technology and the factors involved in designing appropriate studies of it. It is crucial to understand the technical barriers, the role of telesupervisors, the motor improvements that participants can reasonably expect and the process of optimizing IHT-exercise therapy protocols to maximize the benefits of the emerging technology. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. Flavour mixings in flux compactifications

    Buchmuller, Wilfried; Schweizer, Julian

    2017-01-01

    A multiplicity of quark-lepton families can naturally arise as zero-modes in flux compactifications. The flavour structure of quark and lepton mass matrices is then determined by the wave function profiles of the zero-modes. We consider a supersymmetric SO(10) x U(1) model in six dimensions compactified on the orbifold T 2 =Z 2 with Abelian magnetic flux. A bulk 16-plet charged under the U(1) provides the quark-lepton generations whereas two uncharged 10-plets yield two Higgs doublets. Bulk anomaly cancellation requires the presence of additional 16- and 10-plets. The corresponding zero-modes form vectorlike split multiplets that are needed to obtain a successful flavour phenomenology. We analyze the pattern of flavour mixings for the two heaviest families of the Standard Model and discuss possible generalizations to three and more generations.

  14. Superconducting flux flow digital circuits

    Martens, J.S.; Zipperian, T.E.; Hietala, V.M.; Ginley, D.S.; Tigges, C.P.; Phillips, J.M.; Siegal, M.P.

    1993-01-01

    The authors have developed a family of digital logic circuits based on superconducting flux flow transistors that show high speed, reasonable signal levels, large fan-out, and large noise margins. The circuits are made from high-temperature superconductors (HTS) and have been shown to operate at over 90 K. NOR gates have been demonstrated with fan-outs of more than 5 and fully loaded switching times less than a fixture-limited 50 ps. Ring-oscillator data suggest inverter delay times of about 40ps when using a 3-μm linewidths. Simple flip-flops have also been demonstrated showing large noise margins, response times of less than 30 ps, and static power dissipation on the order of 30 nW. Among other uses, this logic family is appropriate as an interface between logic families such as single flux quantum and conventional semiconductor logic

  15. Heisenberg groups and noncommutative fluxes

    Freed, Daniel S.; Moore, Gregory W.; Segal, Graeme

    2007-01-01

    We develop a group-theoretical approach to the formulation of generalized abelian gauge theories, such as those appearing in string theory and M-theory. We explore several applications of this approach. First, we show that there is an uncertainty relation which obstructs simultaneous measurement of electric and magnetic flux when torsion fluxes are included. Next, we show how to define the Hilbert space of a self-dual field. The Hilbert space is Z 2 -graded and we show that, in general, self-dual theories (including the RR fields of string theory) have fermionic sectors. We indicate how rational conformal field theories associated to the two-dimensional Gaussian model generalize to (4k+2)-dimensional conformal field theories. When our ideas are applied to the RR fields of string theory we learn that it is impossible to measure the K-theory class of a RR field. Only the reduction modulo torsion can be measured

  16. Neutron flux enhancement at LASREF

    Sommer, W.F.; Ferguson, P.D.; Wechsler, M.S.

    1992-01-01

    The accelerator at the Los Alamos Meson Physiscs Facility produces a 1 mA beam of protons at an energy of 800 MeV. Since 1985, the Los Alamos Spallation Radiation Effects Facility (LASREF) has made use of the neutron flux that is generated as the incident protons interact with the targets and a copper beam stop. A variety of basic and applied experiments in radiation damage and radiation effects have been completed. Recent studies indicate that the flux at LASREF can be increased by at least a factor of 10 from the present level of about 5 E + 17 m -2 s -1 . This requires changing the beam stop material from Cu to W and optimizing the geometry of the beam-target interaction region. These studies are motivated by the need for a large volume, high energy, and high intensity neutron source in the development of materials for advanced energy concepts such as fusion reactors. (orig.)

  17. Flux through a Markov chain

    Floriani, Elena; Lima, Ricardo; Ourrad, Ouerdia; Spinelli, Lionel

    2016-01-01

    Highlights: • The flux through a Markov chain of a conserved quantity (mass) is studied. • Mass is supplied by an external source and ends in the absorbing states of the chain. • Meaningful for modeling open systems whose dynamics has a Markov property. • The analytical expression of mass distribution is given for a constant source. • The expression of mass distribution is given for periodic or random sources. - Abstract: In this paper we study the flux through a finite Markov chain of a quantity, that we will call mass, which moves through the states of the chain according to the Markov transition probabilities. Mass is supplied by an external source and accumulates in the absorbing states of the chain. We believe that studying how this conserved quantity evolves through the transient (non-absorbing) states of the chain could be useful for the modelization of open systems whose dynamics has a Markov property.

  18. Absolute flux scale for radioastronomy

    Ivanov, V.P.; Stankevich, K.S.

    1986-01-01

    The authors propose and provide support for a new absolute flux scale for radio astronomy, which is not encumbered with the inadequacies of the previous scales. In constructing it the method of relative spectra was used (a powerful tool for choosing reference spectra). A review is given of previous flux scales. The authors compare the AIS scale with the scale they propose. Both scales are based on absolute measurements by the ''artificial moon'' method, and they are practically coincident in the range from 0.96 to 6 GHz. At frequencies above 6 GHz, 0.96 GHz, the AIS scale is overestimated because of incorrect extrapolation of the spectra of the primary and secondary standards. The major results which have emerged from this review of absolute scales in radio astronomy are summarized

  19. ALFA: an automated line fitting algorithm

    Wesson, R.

    2016-03-01

    I present the automated line fitting algorithm, ALFA, a new code which can fit emission line spectra of arbitrary wavelength coverage and resolution, fully automatically. In contrast to traditional emission line fitting methods which require the identification of spectral features suspected to be emission lines, ALFA instead uses a list of lines which are expected to be present to construct a synthetic spectrum. The parameters used to construct the synthetic spectrum are optimized by means of a genetic algorithm. Uncertainties are estimated using the noise structure of the residuals. An emission line spectrum containing several hundred lines can be fitted in a few seconds using a single processor of a typical contemporary desktop or laptop PC. I show that the results are in excellent agreement with those measured manually for a number of spectra. Where discrepancies exist, the manually measured fluxes are found to be less accurate than those returned by ALFA. Together with the code NEAT, ALFA provides a powerful way to rapidly extract physical information from observations, an increasingly vital function in the era of highly multiplexed spectroscopy. The two codes can deliver a reliable and comprehensive analysis of very large data sets in a few hours with little or no user interaction.

  20. Energy Dissipation in the Upper Atmospheres of TRAPPIST-1 Planets

    Cohen, Ofer; Glocer, Alex; Garraffo, Cecilia; Drake, Jeremy J.; Bell, Jared M.

    2018-03-01

    We present a method to quantify the upper limit of the energy transmitted from the intense stellar wind to the upper atmospheres of three of the TRAPPIST-1 planets (e, f, and g). We use a formalism that treats the system as two electromagnetic regions, where the efficiency of the energy transmission between one region (the stellar wind at the planetary orbits) to the other (the planetary ionospheres) depends on the relation between the conductances and impedances of the two regions. Since the energy flux of the stellar wind is very high at these planetary orbits, we find that for the case of high transmission efficiency (when the conductances and impedances are close in magnitude), the energy dissipation in the upper planetary atmospheres is also very large. On average, the Ohmic energy can reach 0.5–1 W m‑2, about 1% of the stellar irradiance and 5–15 times the EUV irradiance. Here, using constant values for the ionospheric conductance, we demonstrate that the stellar wind energy could potentially drive large atmospheric heating in terrestrial planets, as well as in hot Jupiters. More detailed calculations are needed to assess the ionospheric conductance and to determine more accurately the amount of heating the stellar wind can drive in close-orbit planets.

  1. Reentrance of a flux liquid near Hc1 in high-Tc superconductors

    Xing, L.

    1992-01-01

    Previous studies by D. R. Nelson have demonstrated that flux-line wandering in high-T c oxides in fields slightly above H c1 leads to an entangled flux liquid. The statistical mechanics of the flux lines is isomorphic to a two-dimensional (2D) interacting quantum particle system with pairwise interaction potential V(r)=(φ 0 2 /8π 2 λ 2 )K 0 (r/λ), where λ is the magnetic penetration length and K 0 (x) is a modified Bessel function. We have performed a Monte Carlo simulation on the 2D interacting Bose system. The existence of a flux-liquid phase has been observed and the transtion line between flux liquid and flux solid has been identified for a crystalline sample of Y-Ba-Cu-O on the H-T phase diagram over a wide range of temperature. The width of the liquid phase increases with temperature as T 2 at low temperatures, in agreement with the prediction of D. R. Nelson. At high temperatures the width of the liquid phase increases faster than T 2 . We argue that the melting curve eventually crosses over to the high-field vortex-lattice melting curve. Relevance to experiments on high-T c superconductors is mentioned

  2. Improved Mars Upper Atmosphere Climatology

    Bougher, S. W.

    2004-01-01

    The detailed characterization of the Mars upper atmosphere is important for future Mars aerobraking activities. Solar cycle, seasonal, and dust trends (climate) as well as planetary wave activity (weather) are crucial to quantify in order to improve our ability to reasonably depict the state of the Mars upper atmosphere over time. To date, our best information is found in the Mars Global Surveyor (MGS) Accelerometer (ACC) database collected during Phase 1 (Ls = 184 - 300; F10.7 = 70 - 90) and Phase 2 (Ls = 30 - 90; F10.7 = 90 - 150) of aerobraking. This database (100 - 170 km) consists of thermospheric densities, temperatures, and scale heights, providing our best constraints for exercising the coupled Mars General Circulation Model (MGCM) and the Mars Thermospheric General Circulation Model (MTGCM). The Planetary Data System (PDS) contains level 0 and 2 MGS Accelerometer data, corresponding to atmospheric densities along the orbit track. Level 3 products (densities, temperatures, and scale heights at constant altitudes) are also available in the PDS. These datasets provide the primary model constraints for the new MGCM-MTGCM simulations summarized in this report. Our strategy for improving the characterization of the Mars upper atmospheres using these models has been three-fold : (a) to conduct data-model comparisons using the latest MGS data covering limited climatic and weather conditions at Mars, (b) to upgrade the 15-micron cooling and near-IR heating rates in the MGCM and MTGCM codes for ad- dressing climatic variations (solar cycle and seasonal) important in linking the lower and upper atmospheres (including migrating tides), and (c) to exercise the detailed coupled MGCM and MTGCM codes to capture and diagnose the planetary wave (migrating plus non-migrating tidal) features throughout the Mars year. Products from this new suite of MGCM-MTGCM coupled simulations are being used to improve our predictions of the structure of the Mars upper atmosphere for the

  3. line in the spectrum of the HDE 245770 star

    Vojkhanskaya, N.F.

    1980-01-01

    The emission line Hα in the spectrum of HDE 245770 is devided into constant and variable components. The latter is shown to be a line arising in the vicinity of the degenerated components of the system. The radial velocity of the constant part of the line does not vary and equals to +10 km/s. For the variable line component a curve of radial velocities that varies with a period of 104 s is obtained. The period is the same as that of pulsations of the X-ray flux from the variable source A 0535+26

  4. Neutron flux control systems validation

    Hascik, R.

    2003-01-01

    In nuclear installations main requirement is to obtain corresponding nuclear safety in all operation conditions. From the nuclear safety point of view is commissioning and start-up after reactor refuelling appropriate period for safety systems verification. In this paper, methodology, performance and results of neutron flux measurements systems validation is presented. Standard neutron flux measuring chains incorporated into the reactor protection and control system are used. Standard neutron flux measuring chain contains detector, preamplifier, wiring to data acquisition unit, data acquisition unit, wiring to display at control room and display at control room. During reactor outage only data acquisition unit and wiring and displaying at reactor control room is verified. It is impossible to verify detector, preamplifier and wiring to data acquisition recording unit during reactor refuelling according to low power. Adjustment and accurate functionality of these chains is confirmed by start-up rate (SUR) measurement during start-up tests after refuelling of the reactors. This measurement has direct impact to nuclear safety and increase operational nuclear safety level. Briefly description of each measuring system is given. Results are illustrated on measurements performed at Bohunice NPP during reactor start-up tests. Main failures and their elimination are described (Authors)

  5. Surface fluxes in heterogeneous landscape

    Bay Hasager, C

    1997-01-01

    The surface fluxes in homogeneous landscapes are calculated by similarity scaling principles. The methodology is well establish. In heterogeneous landscapes with spatial changes in the micro scale range, i e from 100 m to 10 km, advective effects are significant. The present work focus on these effects in an agricultural countryside typical for the midlatitudes. Meteorological and satellite data from a highly heterogeneous landscape in the Rhine Valley, Germany was collected in the large-scale field experiment TRACT (Transport of pollutants over complex terrain) in 1992. Classified satellite images, Landsat TM and ERS SAR, are used as basis for roughness maps. The roughnesses were measured at meteorological masts in the various cover classes and assigned pixel by pixel to the images. The roughness maps are aggregated, i e spatially averaged, into so-called effective roughness lengths. This calculation is performed by a micro scale aggregation model. The model solves the linearized atmospheric flow equations by a numerical (Fast Fourier Transform) method. This model also calculate maps of friction velocity and momentum flux pixel wise in heterogeneous landscapes. It is indicated how the aggregation methodology can be used to calculate the heat fluxes based on the relevant satellite data i e temperature and soil moisture information. (au) 10 tabs., 49 ills., 223 refs.

  6. Generalized drift-flux correlation

    Takeuchi, K.; Young, M.Y.; Hochreiter, L.E.

    1991-01-01

    A one-dimensional drift-flux model with five conservation equations is frequently employed in major computer codes, such as TRAC-PD2, and in simulator codes. In this method, the relative velocity between liquid and vapor phases, or slip ratio, is given by correlations, rather than by direct solution of the phasic momentum equations, as in the case of the two-fluid model used in TRAC-PF1. The correlations for churn-turbulent bubbly flow and slug flow regimes were given in terms of drift velocities by Zuber and Findlay. For the annular flow regime, the drift velocity correlations were developed by Ishii et al., using interphasic force balances. Another approach is to define the drift velocity so that flooding and liquid hold-up conditions are properly simulated, as reported here. The generalized correlation is used to reanalyze the MB-2 test data for two-phase flow in a large-diameter pipe. The results are applied to the generalized drift flux velocity, whose relationship to the other correlations is discussed. Finally, the generalized drift flux correlation is implemented in TRAC-PD2. Flow reversal from countercurrent to cocurrent flow is computed in small-diameter U-shaped tubes and is compared with the flooding curve

  7. Experiments and simulations of flux rope dynamics in a plasma

    Intrator, Thomas; Abbate, Sara; Ryutov, Dmitri

    2005-10-01

    The behavior of flux ropes is a key issue in solar, space and astrophysics. For instance, magnetic fields and currents on the Sun are sheared and twisted as they store energy, experience an as yet unidentified instability, open into interplanetary space, eject the plasma trapped in them, and cause a flare. The Reconnection Scaling Experiment (RSX) provides a simple means to systematically characterize the linear and non-linear evolution of driven, dissipative, unstable plasma-current filaments. Topology evolves in three dimensions, supports multiple modes, and can bifurcate to quasi-helical equilibria. The ultimate saturation to a nonlinear force and energy balance is the link to a spectrum of relaxation processes. RSX has adjustable energy density β1 to β 1, non-negligible equilibrium plasma flows, driven steady-state scenarios, and adjustable line tying at boundaries. We will show magnetic structure of a kinking, rotating single line tied column, magnetic reconnection between two flux ropes, and pictures of three braided flux ropes. We use computed simulation movies to bridge the gap between the solar physics scales and experimental data with computational modeling. In collaboration with Ivo Furno, Tsitsi Madziwa-Nussinovm Giovanni Lapenta, Adam Light, Los Alamos National Laboratory; Sara Abbate, Torino Polytecnico; and Dmitri Ryutov, Lawrence Livermore National Laboratory.

  8. SPECTRAL OPTICAL MONITORING OF THE NARROW-LINE SEYFERT 1 GALAXY Ark 564

    Shapovalova, A. I.; Burenkov, A. N.; Popović, L. Č.; Kovačević, J.; Chavushyan, V. H.; Valdes, J. R.; Torrealba, J.; Carrasco, L.; Ilić, D.; Kovačević, A.; Kollatschny, W.; Bochkarev, N. G.; León-Tavares, J.; Mercado, A.; Benítez, E.; Dultzin, D.; De la Fuente, E.

    2012-01-01

    We present the results of a long-term (1999-2010) spectral optical monitoring campaign of the active galactic nucleus (AGN) Ark 564, which shows a strong Fe II line emission in the optical. This AGN is a narrow-line Seyfert 1 (NLS1) galaxy, a group of AGNs with specific spectral characteristics. We analyze the light curves of the permitted Hα, Hβ, optical Fe II line fluxes, and the continuum flux in order to search for a time lag between them. Additionally, in order to estimate the contribution of iron lines from different multiplets, we fit the Hβ and Fe II lines with a sum of Gaussian components. We find that during the monitoring period the spectral variation (F max /F min ) of Ark 564 is between 1.5 for Hα and 1.8 for the Fe II lines. The correlation between the Fe II and Hβ flux variations is of higher significance than that of Hα and Hβ (whose correlation is almost absent). The permitted-line profiles are Lorentzian-like and do not change shape during the monitoring period. We investigate, in detail, the optical Fe II emission and find different degrees of correlation between the Fe II emission arising from different spectral multiplets and the continuum flux. The relatively weak and different degrees of correlations between permitted lines and continuum fluxes indicate a rather complex source of ionization of the broad-line emission region.

  9. Heat flux estimation in an infrared experimental furnace using an inverse method

    Le Bideau, P.; Ploteau, J.P.; Glouannec, P.

    2009-01-01

    Infrared emitters are widely used in industrial furnaces for thermal treatment. In these processes, the knowledge of the incident heat flux on the surface of the product is a primary step to optimise the command emitters and for maintenance shift. For these reasons, it is necessary to develop autonomous flux meters that could provide an answer to these requirements. These sensors must give an in-line distribution of infrared irradiation in the tunnel furnace and must be able to measure high heat flux in severe thermal environments. In this paper we present a method for in-line assessments solving an inverse heat conduction problem. A metallic mass is instrumented by thermocouples and an inverse method allows the incident heat flux to be estimated. In the first part, attention is focused on a new design tool, which is a numerical code, for the evaluation of potential options during captor conception. In the second part we present the realization and the test of this 'indirect' flux meter and its associated inverse problem. 'Direct' detectors based on thermoelectric devices are compared with this new flux meter in the same conditions in the same furnace. Results prove that this technique is a reliable method, appropriate for high temperature ambiances. This technique can be applied to furnaces where the heat flux is inaccessible to 'direct' measurements.

  10. Neutron Flux Variation in the Nigeria Research Reactor-1 (NIRR-1)

    Yahaya, M.; Ahmed, Y.A.

    2013-01-01

    In order to ascertain the level of flux variation in one of the inner irradiation channels of the Nigeria Research Reactor-1 (NIRR-1), the irradiation container used for routine activation analysis was employed with copper wires as flux monitors. Measurements were carried out with copper wires arranged in axial direction to determine the thermal neutron flux at selected positions using absolute foil activation method. Our results show that there exists a slight flux variation from one position to another ranging from (4.57±0.21) x 10 11 to (5.20± 0.20) x 10 11 cm -2 s -1 .Individual foil shows slight flux variation from one position to another in the same irradiation container but they all pointed toward a level of consistency in variation in spite of the recent installation of the cadmium lined irradiation channel. The values obtained in this work are in good agreement with the previously measured value of (5.14±0.24) x 10 11 cm -2 s -1 after commissioning of NIRR-1 (Jonah et al., 2005). This shows that the cadmium lined installation does not affect the flux stability. In order to improve the accuracy of NAA using NIRR-l facility, there is need for flux corrections to be made by MNSR users during NAA particularly for samples in the axial position for long irradiation.

  11. Decreasing vortex flux in channels

    Migaj, V.K.; Nosova, I.S.

    1979-01-01

    A new method for reducing vortex flow losses in power plant channels is suggested. The method is based on vortex splitting in vortex flow areas with transverse barriers placed on the channel walls. The upper barrier ends are at the level of the upper boundary of the vortex area and don't protrude to the active flow beyond this boundary. The effectiveness of the method suggested is illustrated taking as an example the investigation of square and flat channels with abrupt widening in one plane, diffusers with widening in one plane, or a rectangualr bend. It is shown that splitting the vortex areas with transverse barriers in the channels results in reduction of hydraulic losses by 10-25%. The above method is characteristic of an extreme simplicity, its application doesn't require changes in the channel shape nor installation of any devices in the flow

  12. Local time dependences of electron flux changes during substorms derived from mulit-satellite observation at synchronous orbit

    Nagai, T.

    1982-01-01

    Energetic electron (energy higher than 2 MeV) observation by a synchronous satellite chain (which consists of GOES 2, GOES 3, and GMS covering the local time extent of approximately 10 hr) have been used to study the large-scale characteristics of the dynamic behavior in the near-earth magnetosphere for substorms, in which low-latitude positive bay aspects are clearly seen in the ground magnetic data. Simultaneous multi-satellite observations have clearly demonstrated the local time dependence of electron flux changes during substorms and the longitudinal extent of electron flux variations. Before a ground substorm onset the energetic electron flux decreases in a wide longitudinal region of the nighttime and the flux decrease is seen even on the afternoonside. For the flux behavior associated with the onset of the substorm expansion phase, there exists a demarcation line, the LT position of which can be represented as LT = 24.3-1.5 K/sub p/. The flux shows a recovery to a normal level east of the demarcation line, and it shows a decrease west of the demarcation line. The region of the flux decrease during the expansion phase is restricted, and it is observed mainly on the afternoonside. The afternoonside flux decrease has a different characteristic from the nightside flux decrease preceding the expansion phase. The nighside flux decrease-recovery sequence is observed in a wide region of more than 6 hr in the nighttime and the center of this variation exists in the premidnight region. It should be noted that the afternoonside flux decrease is not observed for every substorm and the nightside signature noted that the afternoonside flux sometimes becomes a dominent feature even on the afternoonside

  13. Poloidal and toroidal heat flux distribution in the CCT tokamak

    Brown, M.L.; Dhir, V.K.; Taylor, R.J.

    1990-01-01

    Plasma heat flux to the Faraday shield panels of the UCLA Continuous Current Tokamak (CCT) has been measured calorimetrically in order to identify the dominant parameters affecting the spatial distribution of heat deposition. Three heating methods were investigated: audio frequency discharge cleaning, RF heating, and AC ohmic. Significant poloidal asymmetry is present in the heat flux distribution. On the average, the outer panels received 25-30% greater heat flux than the inner ones, with the ratio of maximum to minimum values attaining a difference of more than a factor of 2. As a diagnostic experiment the current to a selected toroidal field coil was reduced in order to locally deflect the toroidal field lines outward in a ripple-like fashion. Greatly enhanced heat deposition (up to a factor of 4) was observed at this location on the outside Faraday panels. The enhancement was greatest for conditions of low toroidal field and low neutral pressure, leading to low plasma densities, for which Coulomb collisions are the smallest. An exponential model based on a heat flux e-folding length describes the experimentally found localization of thermal energy quite adequately. (orig.)

  14. [The smile line, a literature search].

    van der Geld, P A; van Waas, M A

    2003-09-01

    Beautiful teeth, visible when smiling, are in line with the present ideal of beauty. The display of teeth when smiling is determined by the smile line: the projection of the lower border of the upper lip on the maxillary teeth when smiling. On the basis of a literature search the determining methods of the smile line are discussed, demographic data of the position of the smile line are given, and factors of influence are examined. There is no unequivocal method for determining the position of the smile line. A rough distinction can be made between qualitative and (semi)-quantitative methods. The (semi)-quantitative methods have clear advantages for research purposes, but their reliability is unknown. It was demonstrated that among minimally 40% of subjects the maxillary gingiva was not visible when smiling. The mandibular gingiva was not visible when smiling among more than 90% of subjects. Furthermore, it appeared that among women the smile line was on average higher situated than among men and that it has not yet been proven that the smile line will be situated lower when growing older.

  15. Intermittent energy bursts and recurrent topological change of a twisting magnetic flux tube

    Amo, Hiroyoshi; Sato, Tetsuya; Kageyama, Akira.

    1994-09-01

    When continuously twisted, a magnetic flux tube suffers a large kink distortion in the middle part of the tube, like a knot-of-tension instability of a bundle of twisted rubber strings, and reconnection is triggered starting with the twisted field lines and quickly proceeding to the untwisted field lines at the twist-untwist boundary, whereby a giant burst-like energy release takes place. Subsequently, bursts occur intermittently and reconnection advances deeper into the untwisted region. Then, a companion pair of the linked twist-untwist flux tubes reconnect with each other to return to the original axisymmetric tube. The process is thus repeatable. (author)

  16. Reluctance motor employing superconducting magnetic flux switches

    Spyker, R.L.; Ruckstadter, E.J.

    1992-01-01

    This paper reports that superconducting flux switches controlling the magnetic flux in the poles of a motor will enable the implementation of a reluctance motor using one central single phase winding. A superconducting flux switch consists of a ring of superconducting material surrounding a ferromagnetic pole of the motor. When in the superconducting state the switch will block all magnetic flux attempting to flow in the ferromagnetic core. When switched to the normal state the superconducting switch will allow the magnetic flux to flow freely in that pole. By using one high turns-count coil as a flux generator, and selectively channeling flux among the various poles using the superconducting flux switch, 3-phase operation can be emulated with a single-hase central AC source. The motor will also operate when the flux generating coil is driven by a DC current, provided the magnetic flux switches see a continuously varying magnetic flux. Rotor rotation provides this varying flux due to the change in stator pole inductance it produces

  17. Limits for the fluxes of non-conventional particles in muon showers underground

    Dardo, M.; D'Ettorre Piazzoli, B.; Mannocchi, G.; Picchi, P.; Visentin, R.; Sitte, K.

    1975-01-01

    A search for non-conventional massive particles was carried out with the Mt. Cappuccini spark chamber array, by a study of the interactions initiated in the chamber absorbers. Neither an excess of large electro-magnetic cascades, nor an excess of large-angle scattering events was found. Likewise no difference was seen between the interaction features of prompt and of delayed shower particles. The estimated upper limits of the underground fluxes are not or barely consistent with the assumptions of the mandela or passive X-particle hypotheses; zero fluxes appear most likely. (orig./BJ) [de

  18. Excitation of helium resonance lines in solar flares

    Porter, J.G.; Gebbie, K.B.; November, L.J.; Joint Institute for Laboratory Astrophysics, Boulder, CO; National Solar Observatory, Sunspot, NM)

    1985-01-01

    Helium resonance line intensities are calculated for a set of six flare models corresponding to two rates of heating and three widely varying incident fluxes of soft X-rays. The differing ionization and excitation equilibria produced by these models, the processes which dominate the various cases, and the predicted helium line spectra are examined. The line intensities and their ratios are compared with values derived from Skylab NRL spectroheliograms for a class M flare, thus determining which of these models most nearly represents the density vs temperature structure and soft X-ray flux in the flaring solar transition region, and the temperature and dominant mechanaism of formation of the helium line spectrum during a flare. 26 references

  19. Heat tranfer decrease during water boiling in a tube for the heat flux step distribution by the tube length

    Remizov, O.V.; Sergeev, V.V.; Yurkov, Yu.I.

    1983-01-01

    The effect of the heat flux distribution along the circular tube length on supercritical convective heat transfer at parameters typical for steam generators heated by liquid metal is studied. The effect of conditions in a under- and a supercritical zones of a vertical tube with independently heated lower and upper sections on supercritical convective heat transfer is studied on a water circulation loop at 9.8-17.7 MPa pressure and 330-1000 kg/m 2 s mass velocities. The experimental heat fluxes varied within the following limits: at the upper section from 0 to 474 kW/m 2 , at the lower section from 190 to 590 kW/m 2 . Analysis of the obtained data shows that when heat flux changes in the supercritical zone rewetting of the heated surface and simultaneous existence of two critical zones are observed. The effect of heat flux in the supercritical zone on convective heat transfer is ambiguous: the heat flux growth up to 60-100 kW/m 2 leads to increasing minimum values of the heat transfer factor in the supercritical zone, and a further heat flux growth - to their reduction. The conclusion is made that the value of heat flux in the undercritical zone affects convective heat transfer in the supercritical zone mainly through changing the value of critical vapour content

  20. VT Electric Transmission Line Corridors - corridor lines

    Vermont Center for Geographic Information — (Link to Metadata) The ELTRN layer depicts electric transmission line corridors in Vermont. Various methods have been used to digitize features. The data layer...

  1. Development and preliminary validation of flux map processing code MAPLE

    Li Wenhuai; Zhang Xiangju; Dang Zhen; Chen Ming'an; Lu Haoliang; Li Jinggang; Wu Yuanbao

    2013-01-01

    The self-reliant flux map processing code MAPLE was developed by China General Nuclear Power Corporation (CGN). Weight coefficient method (WCM), polynomial expand method (PEM) and thin plane spline (TPS) method were applied to fit the deviation between measured and predicted detector signal results for two-dimensional radial plane, to interpolate or extrapolate the non-instrumented location deviation. Comparison of results in the test cases shows that the TPS method can better capture the information of curved fitting lines than the other methods. The measured flux map data of the Lingao Nuclear Power Plant were processed using MAPLE as validation test cases, combined with SMART code. Validation results show that the calculation results of MAPLE are reasonable and satisfied. (authors)

  2. Method and Apparatus of Implementing a Magnetic Shield Flux Sweeper

    Sadleir, John E. (Inventor)

    2018-01-01

    The present invention relates to a method and apparatus of protecting magnetically sensitive devices with a shield, including: a non-superconducting metal or lower transition temperature (T.sub.c) material compared to a higher transition temperature material, disposed in a magnetic field; means for creating a spatially varying order parameter's |.PSI.(r,T)|.sup.2 in a non-superconducting metal or a lower transition temperature material; wherein a spatially varying order parameter is created by a proximity effect, such that the non-superconducting metal or the lower transition temperature material becomes superconductive as a temperature is lowered, creating a flux-free Meissner state at a center thereof, in order to sweep magnetic flux lines to the periphery.

  3. Relation between gamma-ray emission, radio bursts, and proton fluxes from solar flares

    Fomichev, V.V.; Chertok, I.M.

    1985-01-01

    Data on solar gamma-ray flares, including 24 flares with gamma-ray lines, recorded up to June 1982, are analyzed. It is shown that from the point of view of radio emission the differences between flares with and without gamma-ray lines has a purely quantitative character: the former are accompanied by the most intense microwave bursts. Meter type II bursts are not a distinctive feature of flares with gamma-ray lines. Pulsed flares, regardless of the presence or absence of gamma-ray lines, are not accompanied by significant proton fluxes at the earth. On the whole, contrary to the popular opinion in the literature, flares with gamma-ray lines do not display a deficit of proton flux in interplanetary space in comparison with similar flares without gamma-ray lines. The results of quantitative diagnostics of proton flares based on radio bursts are not at variance with the presence of flares without detectable gamma-ray emission in lines but with a pronounced increase in the proton flux at the earth. 23 references

  4. Allowable minimum upper shelf toughness for nuclear reactor pressure vessels

    Zahoor, A.

    1988-05-01

    The paper develops methodology and procedure for determining the allowable minimum upper shelf toughness for continued safe operation of nuclear reactor pressure vessels. Elastic-plastic fracture mechanics analysis method based on the J-integral tearing modulus (J/T) approach is used. Closed from expressions for the applied J and tearing modulus are presented for finite length, part-throughwall axial flaw with aspect ratio of 1/6. Solutions are then presented for Section III, Appendix G flaw. A simple flaw evaluation procedure that can be applied quickly by utility engineers is presented. An attractive feature of the simple procedure is that tearing modulus calculations are not required by the user, and a solution for the slope of the applied J/T line is provided. Results for the allowable minimum upper shelf toughness are presented for a range of reactor pressure vessel thickness and heatup/cooldown rates.

  5. Allowable minimum upper shelf toughness for nuclear reactor pressure vessels

    Zahoor, A.

    1988-01-01

    The paper develops methodology and procedure for determining the allowable minimum upper shelf toughness for continued safe operation of nuclear reactor pressure vessels. Elastic-plastic fracture mechanics analysis method based on the J-integral tearing modulus (J/T) approach is used. Closed from expressions for the applied J and tearing modulus are presented for finite length, part-throughwall axial flaw with aspect ratio of 1/6. Solutions are then presented for Section III, Appendix G flaw. A simple flaw evaluation procedure that can be applied quickly by utility engineers is presented. An attractive feature of the simple procedure is that tearing modulus calculations are not required by the user, and a solution for the slope of the applied J/T line is provided. Results for the allowable minimum upper shelf toughness are presented for a range of reactor pressure vessel thickness and heatup/cooldown rates. (orig.)

  6. Flux of Cadmium through Euphausiids

    Benayoun, G.; Fowler, S.W.; Oregioni, B.

    1976-01-01

    Flux of the heavy metal cadmium through the euphausiid Meganyctiphanes norvegica was examined. Radiotracer experiments showed that cadmium can be accumulated either directly from water or through the food chain. When comparing equilibrium cadmium concentration factors based on stable element measurements with those obtained from radiotracer experiments, it is evident that exchange between cadmium in the water and that in euphausiid tissue is a relatively slow process, indicating that, in the long term, ingestion of cadmium will probably be the more important route for the accumulation of this metal. Approximately 10% of cadmium ingested by euphausiids was incorporated into internal tissues when the food source was radioactive Artemia. After 1 month cadmium, accumulated directly from water, was found to be most concentrated in the viscera with lesser amounts in eyes, exoskeleton and muscle, respectively. Use of a simple model, based on the assumption that cadmium taken in by the organism must equal cadmium released plus that accumulated in tissue, allowed assessment of the relative importance of various metabolic parameters in controlling the cadmium flux through euphausiids. Fecal pellets, due to their relatively high rate of production and high cadmium content, accounted for 84% of the total cadmium flux through M. norvegica. Comparisons of stable cadmium concentrations in natural euphausiid food and the organism's resultant fecal pellets indicate that the cadmium concentration in ingested material was increased nearly 5-fold during its passage through the euphausiid. From comparisons of all routes by which cadmium can be released from M. norvegica to the water column, it is concluded that fecal pellet deposition represents the principal mechanism effecting the downward vertical transport of cadmium by this species. (author)

  7. Homotopic Polygonal Line Simplification

    Deleuran, Lasse Kosetski

    This thesis presents three contributions to the area of polygonal line simplification, or simply line simplification. A polygonal path, or simply a path is a list of points with line segments between the points. A path can be simplified by morphing it in order to minimize some objective function...

  8. Solar Open Flux Migration from Pole to Pole: Magnetic Field Reversal.

    Huang, G-H; Lin, C-H; Lee, L C

    2017-08-25

    Coronal holes are solar regions with low soft X-ray or low extreme ultraviolet intensities. The magnetic fields from coronal holes extend far away from the Sun, and thus they are identified as regions with open magnetic field lines. Coronal holes are concentrated in the polar regions during the sunspot minimum phase, and spread to lower latitude during the rising phase of solar activity. In this work, we identify coronal holes with outward and inward open magnetic fluxes being in the opposite poles during solar quiet period. We find that during the sunspot rising phase, the outward and inward open fluxes perform pole-to-pole trans-equatorial migrations in opposite directions. The migration of the open fluxes consists of three parts: open flux areas migrating across the equator, new open flux areas generated in the low latitude and migrating poleward, and new open flux areas locally generated in the polar region. All three components contribute to the reversal of magnetic polarity. The percentage of contribution from each component is different for different solar cycle. Our results also show that the sunspot number is positively correlated with the lower-latitude open magnetic flux area, but negatively correlated with the total open flux area.

  9. Magnetic Flux Cancellation as the Origin of Solar Quiet-region Pre-jet Minifilaments

    Panesar, Navdeep K.; Sterling, Alphonse C.; Moore, Ronald L., E-mail: navdeep.k.panesar@nasa.gov [NASA Marshall Space Flight Center, Huntsville, AL 35812 (United States)

    2017-08-01

    We investigate the origin of 10 solar quiet-region pre-jet minifilaments , using EUV images from the Solar Dynamics Observatory ( SDO )/Atmospheric Imaging Assembly (AIA) and magnetograms from the SDO Helioseismic and Magnetic Imager (HMI). We recently found that quiet-region coronal jets are driven by minifilament eruptions, where those eruptions result from flux cancellation at the magnetic neutral line under the minifilament. Here, we study the longer-term origin of the pre-jet minifilaments themselves. We find that they result from flux cancellation between minority-polarity and majority-polarity flux patches. In each of 10 pre-jet regions, we find that opposite-polarity patches of magnetic flux converge and cancel, with a flux reduction of 10%–40% from before to after the minifilament appears. For our 10 events, the minifilaments exist for periods ranging from 1.5 hr to 2 days before erupting to make a jet. Apparently, the flux cancellation builds a highly sheared field that runs above and traces the neutral line, and the cool transition region plasma minifilament forms in this field and is suspended in it. We infer that the convergence of the opposite-polarity patches results in reconnection in the low corona that builds a magnetic arcade enveloping the minifilament in its core, and that the continuing flux cancellation at the neutral line finally destabilizes the minifilament field so that it erupts and drives the production of a coronal jet. Thus, our observations strongly support that quiet-region magnetic flux cancellation results in both the formation of the pre-jet minifilament and its jet-driving eruption.

  10. Proposal of an alternative upper divertor in ASDEX Upgrade supported by EMC3-EIRENE simulations

    T. Lunt

    2017-08-01

    Full Text Available We discuss the benefits of installing a pair of in-vessel coils with currents |Ifx| ≲ 50 kAt in the upper divertor of ASDEX Upgrade (AUG to study a series of ‘alternative’ divertor configurations, like the Snowflake (SF and the X-divertor (XD, that are currently considered as alternative solutions for the power exhaust problem. The possibility of operating the standard lower single-null (SN and double-null (DN would be preserved. Potential effects to reduce the peak parallel- and/or perpendicular heat flux are predicted from a simple geometrical-diffusive model as well as by numerical EMC3-EIRENE simulations for pure deuterium attached conditions with spatially constant diffusion coefficients. Beyond that a series of other potential transport- and radiation related heat flux mitigation effects are identified and could be studied experimentally with the modified upper divertor in the high-power divertor Tokamak AUG.

  11. Framework for Flux Qubit Design

    Yan, Fei; Kamal, Archana; Krantz, Philip; Campbell, Daniel; Kim, David; Yoder, Jonilyn; Orlando, Terry; Gustavsson, Simon; Oliver, William; Engineering Quantum Systems Team

    A qubit design for higher performance relies on the understanding of how various qubit properties are related to design parameters. We construct a framework for understanding the qubit design in the flux regime. We explore different parameter regimes, looking for features desirable for certain purpose in the context of quantum computing. This research was funded by the Office of the Director of National Intelligence (ODNI), Intelligence Advanced Research Projects Activity (IARPA) via MIT Lincoln Laboratory under Air Force Contract No. FA8721-05-C-0002.

  12. Four-collector flux sensor

    Wiegand, W.J. Jr.; Bullis, R.H.; Mongeon, R.J.

    1980-01-01

    A flowmeter based on ion drift techniques was developed for measuring the rate of flow of a fluid through a given cross-section. Ion collectors are positioned on each side of an immediately adjacent to ion source. When air flows axially through the region in which ions are produced and appropriate electric fields are maintained between the collectors, an electric current flows to each collector due to the net motion of the ions. The electric currents and voltages and other parameters which define the flow are combined in an electric circuit so that the flux of the fluid can be determined. (DN)

  13. Composites for Exploration Upper Stage

    Fikes, J. C.; Jackson, J. R.; Richardson, S. W.; Thomas, A. D.; Mann, T. O.; Miller, S. G.

    2016-01-01

    The Composites for Exploration Upper Stage (CEUS) was a 3-year, level III project within the Technology Demonstration Missions program of the NASA Space Technology Mission Directorate. Studies have shown that composites provide important programmatic enhancements, including reduced weight to increase capability and accelerated expansion of exploration and science mission objectives. The CEUS project was focused on technologies that best advanced innovation, infusion, and broad applications for the inclusion of composites on future large human-rated launch vehicles and spacecraft. The benefits included near- and far-term opportunities for infusion (NASA, industry/commercial, Department of Defense), demonstrated critical technologies and technically implementable evolvable innovations, and sustained Agency experience. The initial scope of the project was to advance technologies for large composite structures applicable to the Space Launch System (SLS) Exploration Upper Stage (EUS) by focusing on the affordability and technical performance of the EUS forward and aft skirts. The project was tasked to develop and demonstrate critical composite technologies with a focus on full-scale materials, design, manufacturing, and test using NASA in-house capabilities. This would have demonstrated a major advancement in confidence and matured the large-scale composite technology to a Technology Readiness Level 6. This project would, therefore, have bridged the gap for providing composite application to SLS upgrades, enabling future exploration missions.

  14. Six upper incisors: what's next?

    Berneburg, Mirjam; Meller, Christian

    2016-01-01

    This case report describes our therapeutic approach taken in a girl with eruption disturbance of the upper anterior teeth. Two supernumerary teeth were involved, which required a combination of orthodontic and surgical treatment. The initial situation in the upper anterior segment was characterized by two supernumerary mesial incisors, ectopic eruption of the distally located lateral incisors, and crowded tooth buds in the canine areas. Key decisions had to be made as to whether any teeth needed to be extracted and, if so, regarding the timing and sites of extraction. Removing teeth too early would have preempted a complete assessment of tooth quality, whereas late extraction would have carried a risk of eruption disturbance. Once the distal lateral incisors had erupted, the supernumerary mesial incisors were extracted and the central incisors (initially located in between) mesialized with a bracket appliance. Following space closure and mesialization of the lateral incisors, a functional appliance was used. Tooth 13 was erupting, while tooth 23 was displaced and subsequently aligned as part of the final bracket treatment. To successfully treat eruption disturbances, a careful diagnostic workup is essential, including informative radiographs, personalized treatment planning, and correct decision-making as to whether teeth need to be extracted and regarding the timing and sites of extraction. Finally, the eruption of the canines should be monitored.

  15. Modeling and interpretation of line observations*

    Kamp Inga

    2015-01-01

    Full Text Available Models for the interpretation of line observations from protoplanetary disks are summarized. The spectrum ranges from 1D LTE slab models to 2D thermo-chemical radiative transfer models and their use depends largely on the type/nature of observational data that is analyzed. I discuss the various types of observational data and their interpretation in the context of disk physical and chemical properties. The most simple spatially and spectral unresolved data are line fluxes, which can be interpreted using so-called Boltzmann diagrams. The interpretation is often tricky due to optical depth and non-LTE effects and requires care. Line profiles contain kinematic information and thus indirectly the spatial origin of the emission. Using series of line profiles, we can for example deduce radial temperature gradients in disks (CO pure rotational ladder. Spectro-astrometry of e.g. CO ro-vibrational line profiles probes the disk structure in the 1–30 AU region, where planet formation through core accretion should be most efficient. Spatially and spectrally resolved line images from (submm interferometers are the richest datasets we have to date and they enable us to unravel exciting details of the radial and vertical disk structure such as winds and asymmetries.

  16. Collisionless reconnection: magnetic field line interaction

    R. A. Treumann

    2012-10-01

    Full Text Available Magnetic field lines are quantum objects carrying one quantum Φ0 = 2πh/e of magnetic flux and have finite radius λm. Here we argue that they possess a very specific dynamical interaction. Parallel field lines reject each other. When confined to a certain area they form two-dimensional lattices of hexagonal structure. We estimate the filling factor of such an area. Anti-parallel field lines, on the other hand, attract each other. We identify the physical mechanism as being due to the action of the gauge potential field, which we determine quantum mechanically for two parallel and two anti-parallel field lines. The distortion of the quantum electrodynamic vacuum causes a cloud of virtual pairs. We calculate the virtual pair production rate from quantum electrodynamics and estimate the virtual pair cloud density, pair current and Lorentz force density acting on the field lines via the pair cloud. These properties of field line dynamics become important in collisionless reconnection, consistently explaining why and how reconnection can spontaneously set on in the field-free centre of a current sheet below the electron-inertial scale.

  17. Measuring planetary neutron albedo fluxes by remote gamma-ray sensing

    Haines, E.L.; Metzger, A.E.

    1984-01-01

    A remote-sensing γ-ray spectrometer (GRS) is capable of measuring planetary surface composition through the detection of characteristic gamma rays. In addition, the planetary neutron leakage flux may be detected by means of a thin neutron absorber surrounding the γ-ray detector which converts the neutron flux into a γ-ray flux having a unique energy signature. The γ rays representing the neutron flux are observed against interference consisting of cosmic γ rays, planetary continuum and line emission, and a variety of gamma rays arising from cosmic-ray particle interactions with the γ-ray spectrometer and spacecraft (SC). In this paper the amplitudes of planetary and non-planetary neutron fluxes are assessed and their impact on the sensitivity of measurement is calculated for a lunar orbiter mission and a comet nucleus rendezvous mission. For a 100 h observation period from an altitude of 100 km, a GRS on a lunar orbiter can detect a thermal neutron albedo flux as low as 0.002 cm -2 s -1 and measure the expected flux of approx.=0.6 cm -2 s -1 with an uncertainty of 0.001 cm -2 s -1 . A GRS rendezvousing with a comet at a distance equal to the radius of the comet's nucleus, again for a 100 h observation time, should detect a thermal neutron albedo flux at a level of 0.006 cm -2 s -1 and measure the expected flux of approx.=0.4 cm -2 s -1 with an uncertainty of 0.004 cm -2 s -1 . Mapping the planetary neutron flux jointly with the direct detection of H will not only provide a more accurate model for translating observed γ-ray fluxes into concentrations but will also extend the effective sampling depth and should provide a capability for simple stratigraphic modeling of hydrogen. (orig.)

  18. Structures of interplanetary magnetic flux ropes and comparison with their solar sources

    Hu, Qiang [Department of Space Science/CSPAR, University of Alabama in Huntsville, Huntsville, AL 35805 (United States); Qiu, Jiong [Department of Physics, Montana State University, Bozeman, MT 59717-3840 (United States); Dasgupta, B.; Khare, A.; Webb, G. M., E-mail: qh0001@uah.edu, E-mail: qiu@physics.montana.edu [Center for Space Plasma and Aeronomic Research (CSPAR), University of Alabama in Huntsville, Huntsville, AL 35805 (United States)

    2014-09-20

    Whether a magnetic flux rope is pre-existing or formed in situ in the Sun's atmosphere, there is little doubt that magnetic reconnection is essential to release the flux rope during its ejection. During this process, the question remains: how does magnetic reconnection change the flux-rope structure? In this work, we continue with the original study of Qiu et al. by using a larger sample of flare-coronal mass ejection (CME)-interplanetary CME (ICME) events to compare properties of ICME/magnetic cloud (MC) flux ropes measured at 1 AU and properties of associated solar progenitors including flares, filaments, and CMEs. In particular, the magnetic field-line twist distribution within interplanetary magnetic flux ropes is systematically derived and examined. Our analysis shows that, similar to what was found before, for most of these events, the amount of twisted flux per AU in MCs is comparable with the total reconnection flux on the Sun, and the sign of the MC helicity is consistent with the sign of the helicity of the solar source region judged from the geometry of post-flare loops. Remarkably, we find that about half of the 18 magnetic flux ropes, most of them associated with erupting filaments, have a nearly uniform and relatively low twist distribution from the axis to the edge, and the majority of the other flux ropes exhibit very high twist near the axis, up to ≳ 5 turns per AU, which decreases toward the edge. The flux ropes are therefore not linearly force-free. We also conduct detailed case studies showing the contrast of two events with distinct twist distribution in MCs as well as different flare and dimming characteristics in solar source regions, and discuss how reconnection geometry reflected in flare morphology may be related to the structure of the flux rope formed on the Sun.

  19. Magnetic Flux Rope Identification and Characterization from Observationally Driven Solar Coronal Models

    Lowder, Chris; Yeates, Anthony

    2017-09-01

    Formed through magnetic field shearing and reconnection in the solar corona, magnetic flux ropes are structures of twisted magnetic field, threaded along an axis. Their evolution and potential eruption are of great importance for space weather. Here we describe a new methodology for the automated detection of flux ropes in simulated magnetic fields, utilizing field-line helicity. Our Flux Rope Detection and Organization (FRoDO) code, which measures the magnetic flux and helicity content of pre-erupting flux ropes over time, as well as detecting eruptions, is publicly available. As a first demonstration, the code is applied to the output from a time-dependent magnetofrictional model, spanning 1996 June 15-2014 February 10. Over this period, 1561 erupting and 2099 non-erupting magnetic flux ropes are detected, tracked, and characterized. For this particular model data, erupting flux ropes have a mean net helicity magnitude of 2.66× {10}43 Mx2, while non-erupting flux ropes have a significantly lower mean of 4.04× {10}42 Mx2, although there is overlap between the two distributions. Similarly, the mean unsigned magnetic flux for erupting flux ropes is 4.04× {10}21 Mx, significantly higher than the mean value of 7.05× {10}20 Mx for non-erupting ropes. These values for erupting flux ropes are within the broad range expected from observational and theoretical estimates, although the eruption rate in this particular model is lower than that of observed coronal mass ejections. In the future, the FRoDO code will prove to be a valuable tool for assessing the performance of different non-potential coronal simulations and comparing them with observations.

  20. Magnet power supply and beam line control for a secondary beam line K6

    Suzuki, Y.; Takasaki, M.; Minakawa, M.; Ishii, H.; Kato, Y.; Ieiri, M.; Tanaka, K.H.; Noumi, H.; Yamanoi, Y.

    1992-01-01

    K6 is a secondary separated-beam line with momentum range up to 2.0 GeV/c in the north experimental hall at the KEK 12 GeV Proton Synchrotron (KEK-PS). On the construction, newly developed magnet power supplies (MPSs), in each of them a microprocessor is embedded, are introduced. The features of the MPS are as follows: 1, The MPS is connected to an upper-level beam line controller (BLC) by GPIB highway for exchanging simple messages. 2, All the operations of the MPS are supervised by the microprocessor, which has its individual parameters and fault messages. It reduces the load of the upper-level controller. 3, The MPS has functions to inspect itself and to report the result. It saves much time and labor of maintenance. (author)

  1. An Energy-Stabilized Varied-Line-Space-Monochromator Undulator Beam Line for PEEM Illumination and Magnetic Circular Dichroism

    Warwick, Tony; McKinney, Wayne; Domning, Ed; Doran, Andrew; Padmore, Howard

    2006-01-01

    A new undulator beam line has been built and commissioned at the Advanced Light Source for illumination of the PEEM3 microscope. The beam line delivers high flux beams over an energy range from C1s through the transition metals to include the M edges of the magnetic rare earth elements. We present details of the optical design, and data on the performance of the zero-order tracking of the photon energy

  2. Flux rope breaking and formation of a rotating blowout jet

    Joshi, Navin Chandra; Nishizuka, Naoto; Filippov, Boris; Magara, Tetsuya; Tlatov, Andrey G.

    2018-05-01

    We analysed a small flux rope eruption converted into a helical blowout jet in a fan-spine configuration using multiwavelength observations taken by Solar Dynamics Observatory, which occurred near the limb on 2016 January 9. In our study, first, we estimated the fan-spine magnetic configuration with the potential-field calculation and found a sinistral small filament inside it. The filament along with the flux rope erupted upwards and interacted with the surrounding fan-spine magnetic configuration, where the flux rope breaks in the middle section. We observed compact brightening, flare ribbons, and post-flare loops underneath the erupting filament. The northern section of the flux rope reconnected with the surrounding positive polarity, while the southern section straightened. Next, we observed the untwisting motion of the southern leg, which was transformed into a rotating helical blowout jet. The sign of the helicity of the mini-filament matches the one of the rotating jets. This is consistent with recent jet models presented by Adams et al. and Sterling et al. We focused on the fine thread structure of the rotating jet and traced three blobs with the speed of 60-120 km s- 1, while the radial speed of the jet is ˜400 km s- 1. The untwisting motion of the jet accelerated plasma upwards along the collimated outer spine field lines, and it finally evolved into a narrow coronal mass ejection at the height of ˜9Rsun. On the basis of detailed analysis, we discussed clear evidence of the scenario of the breaking of the flux rope and the formation of the helical blowout jet in the fan-spine magnetic configuration.

  3. HOOKED FLARE RIBBONS AND FLUX-ROPE-RELATED QSL FOOTPRINTS

    Zhao, Jie; Li, Hui [Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, CAS, Nanjing 210008 (China); Gilchrist, Stuart A.; Aulanier, Guillaume; Schmieder, Brigitte; Pariat, Etienne, E-mail: nj.lihui@pmo.ac.cn [LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, Univ. Paris-Diderot, Sorbonne Paris Cité, 5 place Jules Janssen, F-92195 Meudon (France)

    2016-05-20

    We studied the magnetic topology of active region 12158 on 2014 September 10 and compared it with the observations before and early in the flare that begins at 17:21 UT (SOL2014-09-10T17:45:00). Our results show that the sigmoidal structure and flare ribbons of this active region observed by the Solar Dynamics Observatory /Atmospheric Imaging Assembly can be well reproduced from a Grad–Rubin nonlinear force-free field extrapolation method. Various inverse-S- and inverse-J-shaped magnetic field lines, which surround a coronal flux rope, coincide with the sigmoid as observed in different extreme-ultraviolet wavelengths, including its multithreaded curved ends. Also, the observed distribution of surface currents in the magnetic polarity where it was not prescribed is well reproduced. This validates our numerical implementation and setup of the Grad–Rubin method. The modeled double inverse-J-shaped quasi-separatrix layer (QSL) footprints match the observed flare ribbons during the rising phase of the flare, including their hooked parts. The spiral-like shape of the latter may be related to a complex pre-eruptive flux rope with more than one turn of twist, as obtained in the model. These ribbon-associated flux-rope QSL footprints are consistent with the new standard flare model in 3D, with the presence of a hyperbolic flux tube located below an inverse-teardrop-shaped coronal QSL. This is a new step forward forecasting the locations of reconnection and ribbons in solar flares and the geometrical properties of eruptive flux ropes.

  4. HOOKED FLARE RIBBONS AND FLUX-ROPE-RELATED QSL FOOTPRINTS

    Zhao, Jie; Li, Hui; Gilchrist, Stuart A.; Aulanier, Guillaume; Schmieder, Brigitte; Pariat, Etienne

    2016-01-01

    We studied the magnetic topology of active region 12158 on 2014 September 10 and compared it with the observations before and early in the flare that begins at 17:21 UT (SOL2014-09-10T17:45:00). Our results show that the sigmoidal structure and flare ribbons of this active region observed by the Solar Dynamics Observatory /Atmospheric Imaging Assembly can be well reproduced from a Grad–Rubin nonlinear force-free field extrapolation method. Various inverse-S- and inverse-J-shaped magnetic field lines, which surround a coronal flux rope, coincide with the sigmoid as observed in different extreme-ultraviolet wavelengths, including its multithreaded curved ends. Also, the observed distribution of surface currents in the magnetic polarity where it was not prescribed is well reproduced. This validates our numerical implementation and setup of the Grad–Rubin method. The modeled double inverse-J-shaped quasi-separatrix layer (QSL) footprints match the observed flare ribbons during the rising phase of the flare, including their hooked parts. The spiral-like shape of the latter may be related to a complex pre-eruptive flux rope with more than one turn of twist, as obtained in the model. These ribbon-associated flux-rope QSL footprints are consistent with the new standard flare model in 3D, with the presence of a hyperbolic flux tube located below an inverse-teardrop-shaped coronal QSL. This is a new step forward forecasting the locations of reconnection and ribbons in solar flares and the geometrical properties of eruptive flux ropes.

  5. Limits on diffuse fluxes of high energy extraterrestrial neutrinos with the AMANDA-B10 detector

    Ahrens, J.; Bai, X.; Barwick, S.W.; Bay, R.C.; Becka, T.; Becker, K.-H.; Bernardini, E.; Bertrand, D.; Binon, F.; Boeser, S.; Botner, O.; Bouchta, A.; Bouhali, O.; Burgess, T.; Carius, S.; Castermans, T.; Chirkin, D.; Conrad, J.; Cooley, J.; Cowen, D.F.; Davour, A.; De Clercq, C.; DeYoung, T.; Desiati, P.; Doksus, P.; Ekstrom, P.; Feser, T.; Gaisser, T.K.; Ganugapati, R.; Gaug, M.; Geenen, H.; Gerhardt, L.; Goldschmidt, A.; Hallgren, A.; Halzen, F.; Hanson, K.; Hardtke, R.; Hauschildt, T.; Hellwig, M.; Herquet, P.; Hill, G.C.; Hulth, P.O.; Hughey, B.; Hultqvist, K.; Hundertmark, S.; Jacobsen, J.; Karle, A.; Kuehn, K.; Kim, J.; Kopke, L.; Kowalski, M.; Lamoureux, J.I.; Leich, H.; Leuthold, M.; Lindahl, P.; Liubarsky, I.; Madsen, J.; Mandli, K.; Marciniewski, P.; Matis, H.S.; McParland, C.P.; Messarius, T.; Miller, T.C.; Minaeva, Y.; Miocinovic, P.; Mock, P.C.; Morse, R.; Neunhoffer, T.; Niessen, P.; Nygren, D.R.; Ogelman, H.; Olbrechts, P.; Perez de los Heros, C.; Pohl, A.C.; Porrata, R.; Price, P.B.; Przybylski, G.T.; Rawlins, K.; Resconi, E.; Rhode, W.; Ribordy, M.; Richter, S.; Rodriguez Martino, J.; Romenesko, P.; Ross, D.; Sander, H.-G.; Schlenstedt, S.; Schinarakis, K.; Schmidt, T.; Schneider, D.; Schwarz, R.; Silvestri, A.; Solarz, M.; Stamatikos, M.; Spiczak, G.M.; Spiering, C.; Steele, D.; Steffen, P.; Stokstad, R.G.; Sulanke, K.-H.; Taboada, I.; Tilav, S.; Wagner, W.; Walck, C.; Wang, Y.-R.; Wiebusch, C.H.; Wiedemann, C.; Wischnewski, R.; Wissing, H.; Woschnagg, K.; Wu, W.; Yodh, G.; Young, S.

    2003-01-01

    Data from the AMANDA-B10 detector taken during the austral winter of 1997 have been searched for a diffuse flux of high energy extraterrestrial muon-neutrinos, as predicted from, e.g., the sum of all active galaxies in the universe. This search yielded no excess events above those expected from the background atmospheric neutrinos, leading to upper limits on the extraterrestrial neutrino flux. For an assumed E -2 spectrum, a 90 percent classical confidence level upper limit has been placed at a level E 2 Phi(E) = 8.4 x 10 -7 GeV cm -2 s -1 1 sr -1 (for a predominant neutrino energy range 6-1000 TeV) which is the most restrictive bound placed by any neutrino detector. When specific predicted spectral forms are considered, it is found that some are excluded

  6. Neutron flux enhancement at LASREF

    Sommer, W.F.; Ferguson, P.D.; Wechsler, M.S.

    1991-01-01

    The accelerator at the Los Alamos Meson Physics Facility produces a 1-mA beam of protons at an energy of 800 MeV. Since 1985, the Los Alamos Spallation Radiation Effects Facility (LASREF) has made use of the neutron flux that is generated as the incident protons interact with the nuclei in targets and a copper beam stop. A variety of basic and applied experiments in radiation damage and radiation effects have been completed. Recent studies indicate that the flux at LASREF can be increased by at least a factor of ten from the present level of about 5 E+17 m -2 s -1 . This requires changing the beam-stop material from Cu to W and optimizing the geometry of the beam-target interaction region. These studies are motivated by the need for a large volume, high energy, and high intensity neutron source in the development of materials for advanced energy concepts such as fusion reactors. 18 refs., 7 figs., 2 tabs

  7. Neutron flux enhancement at LASREF

    Sommer, W.F. (Los Alamos National Lab., Los Alamos, NM (United States)); Ferguson, P.D. (Univ. of Missouri, Rolla, MO (United States)); Wechsler, M.S. (Iowa State Univ., Ames, IA (United States))

    1992-09-01

    The accelerator at the Los Alamos Meson Physiscs Facility produces a 1 mA beam of protons at an energy of 800 MeV. Since 1985, the Los Alamos Spallation Radiation Effects Facility (LASREF) has made use of the neutron flux that is generated as the incident protons interact with the targets and a copper beam stop. A variety of basic and applied experiments in radiation damage and radiation effects have been completed. Recent studies indicate that the flux at LASREF can be increased by at least a factor of 10 from the present level of about 5 E + 17 m[sup -2] s[sup -1]. This requires changing the beam stop material from Cu to W and optimizing the geometry of the beam-target interaction region. These studies are motivated by the need for a large volume, high energy, and high intensity neutron source in the development of materials for advanced energy concepts such as fusion reactors. (orig.).

  8. Simultaneously estimation for surface heat fluxes of steel slab in a reheating furnace based on DMC predictive control

    Li, Yanhao; Wang, Guangjun; Chen, Hong

    2015-01-01

    The predictive control theory is utilized for the research of a simultaneous estimation of heat fluxes through the upper, side and lower surface of a steel slab in a walking beam type rolling steel reheating furnace. An inverse algorithm based on dynamic matrix control (DMC) is established. That is, each surface heat flux of a slab is simultaneously estimated through rolling optimization on the basis of temperature measurements in selected points of its interior by utilizing step response function as predictive model of a slab's temperature. The reliability of the DMC results is enhanced without prior assuming specific functions of heat fluxes over a period of future time. The inverse algorithm proposed a respective regularization to effectively improve the stability of the estimated results by considering obvious strength differences between the upper as well as lower and side surface heat fluxes of the slab. - Highlights: • The predictive control theory is adopted. • An inversion scheme based on DMC is established. • Upper, side and lower surface heat fluxes of slab are estimated based DMC. • A respective regularization is proposed to improve the stability of results

  9. THE MASS OF KOI-94d AND A RELATION FOR PLANET RADIUS, MASS, AND INCIDENT FLUX

    Weiss, Lauren M.; Marcy, Geoffrey W.; Isaacson, Howard; Kolbl, Rea; Rowe, Jason F.; Howell, Steve B.; Howard, Andrew W.; Fortney, Jonathan J.; Miller, Neil; Demory, Brice-Olivier; Seager, Sara; Fischer, Debra A.; Adams, Elisabeth R.; Dupree, Andrea K.; Johnson, John Asher; Horch, Elliott P.; Everett, Mark E.; Fabrycky, Daniel C.

    2013-01-01

    We measure the mass of a modestly irradiated giant planet, KOI-94d. We wish to determine whether this planet, which is in a 22 day orbit and receives 2700 times as much incident flux as Jupiter, is as dense as Jupiter or rarefied like inflated hot Jupiters. KOI-94 also hosts at least three smaller transiting planets, all of which were detected by the Kepler mission. With 26 radial velocities of KOI-94 from the W. M. Keck Observatory and a simultaneous fit to the Kepler light curve, we measure the mass of the giant planet and determine that it is not inflated. Support for the planetary interpretation of the other three candidates comes from gravitational interactions through transit timing variations, the statistical robustness of multi-planet systems against false positives, and several lines of evidence that no other star resides within the photometric aperture. We report the properties of KOI-94b (M P = 10.5 ± 4.6 M ⊕ , R P = 1.71 ± 0.16 R ⊕ , P = 3.74 days), KOI-94c (M P = 15.6 +5.7 -15.6 M ⊕ , R P = 4.32 ± 0.41 R ⊕ , P = 10.4 days), KOI-94d (M P = 106 ± 11 M ⊕ , R P = 11.27 ± 1.06 R ⊕ , P = 22.3 days), and KOI-94e (M P = 35 +18 -28 M ⊕ , R P = 6.56 ± 0.62 R ⊕ , P = 54.3 days). The radial velocity analyses of KOI-94b and KOI-94e offer marginal (>2σ) mass detections, whereas the observations of KOI-94c offer only an upper limit to its mass. Using the KOI-94 system and other planets with published values for both mass and radius (138 exoplanets total, including 35 with M P ⊕ ), we establish two fundamental planes for exoplanets that relate their mass, incident flux, and radius from a few Earth masses up to 13 Jupiter masses: (R P /R ⊕ ) = 1.78(M P /M ⊕ ) 0.53 (F/erg s –1 cm –2 ) –0.03 for M P ⊕ , and R P /R ⊕ = 2.45(M P /M ⊕ ) –0.039 (F/erg s –1 cm –2 ) 0.094 for M P > 150 M ⊕ . These equations can be used to predict the radius or mass of a planet.

  10. Low energy neutral particle fluxes in the JET divertor

    Reichle, R.; Horton, L.D.; Ingesson, L.C.; Jaeckel, H.J.; McCormick, G.K.; Loarte, A.; Simonini, R.; Stamp, M.F.

    1997-01-01

    First measurements are presented of the total power loss through neutral particles and their average energy in the JET divertor. The method used distinguishes between the heat flux and the electromagnetic radiation on bolometers. This is done by comparing measurements from inside the divertor either with opposite lines of sight or with a tomographic reconstruction of the radiation. The typical value of the total power loss in the divertor through neutrals is about 1 MW. The average energy of the neutral particles at the inner divertor leg is 1.5-3 eV when detachment is in progress, which agrees with EDGE2D/NIMBUS modelling. (orig.)

  11. Asymptotic properties of blow-up solutions in reaction-diffusion equations with nonlocal boundary flux

    Liu, Bingchen; Dong, Mengzhen; Li, Fengjie

    2018-04-01

    This paper deals with a reaction-diffusion problem with coupled nonlinear inner sources and nonlocal boundary flux. Firstly, we propose the critical exponents on nonsimultaneous blow-up under some conditions on the initial data. Secondly, we combine the scaling technique and the Green's identity method to determine four kinds of simultaneous blow-up rates. Thirdly, the lower and the upper bounds of blow-up time are derived by using Sobolev-type differential inequalities.

  12. Calculation of fluxes through a repository caused by a local well

    Thunvik, R.

    1983-05-01

    The purpose of the present study is to roughly estimate the ground water flux through a radioactive repository in relation to the flux into a local well under various conditions. The well is assumed to be located at a depth of either 60 or 200 metres below the ground surface. Two main settings are considered, in one the well is located in a vertical fracture zone at a distance of 100 metres from one of the outer edges of the repository. The withdrawal from the well is assumed to be 6 m 3 /day. The flow domain is characterized by a rather low permeability. The boundary conditions considered are either a continuously saturated upper boundary and impervious lateral boundaries, or a phreatic upper boundary and hydrostatic lateral boundaries. The ratio of the flux through the repository to the flux into the well was obtained to be in the range from about 10- 5 to 10- 3 , depending on the boundary conditions and the depth of the well. The lowest figures were obtained in the examples, in which the upper boundary was assumed to be continually saturated. It is concluded that these examples may be considered representative of the actual flow problem. This conclusion is based upon the fact that in the case of a phreatic boundary the drawdown caused by the well was very small and the flow responses were very slow, implying that rather a small infiltration rate is requied to maintain saturated conditions at the upper boundary. The regional gradients caused by the well were rather small in comparison with the typically naturally occurring gradients. The flow to the well will therefore have little influence on the regional flow pattern in most practical cases. (author)

  13. A novel polarization interferometer for measuring upper atmospheric winds

    Ting-Kui, Mu; Chun-Min, Zhang

    2010-01-01

    A static polarization interferometer for measuring upper atmospheric winds is presented, based on two Savart plates with their optical axes perpendicular to each other. The principle and characteristics of the interferometer are described. The interferometer with a wide field of view can offer a stable benchmark optical path difference over a specified spectral region of 0.55–0.63 μm because there are no quarter wave plates. Since the instrument employs a straight line common-path configuration but without moving parts and slits, it is very compact, simple, inherently robust and has high throughput. The paper is limited to a theoretical analysis. (general)

  14. Recent Update of Embolization of Upper Gastrointestinal Tract Bleeding

    Shin, Ji Hoon [Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    2012-02-15

    Nonvariceal upper gastrointestinal (UGI) bleeding is a frequent complication with significant morbidity and mortality. Although endoscopic hemostasis remains the initial treatment modality, severe bleeding despite endoscopic management occurs in 5-10% of patients, necessitating surgery or interventional embolotherapy. Endovascular embolotherapy is now considered the first-line therapy for massive UGI bleeding that is refractory to endoscopic management. Interventional radiologists need to be familiar with the choice of embolic materials, technical aspects of embolotherapy, and the factors affecting the favorable or unfavorable outcomes after embolotherapy for UGI bleeding.

  15. Updates on upper eyelid blepharoplasty

    Kasturi Bhattacharjee

    2017-01-01

    Full Text Available The human face is composed of small functional and cosmetic units, of which the eyes and periocular region constitute the main point of focus in routine face-to-face interactions. This dynamic region plays a pivotal role in the expression of mood, emotion, and character, thus making it the most relevant component of the facial esthetic and functional unit. Any change in the periocular unit leads to facial imbalance and functional disharmony, leading both the young and the elderly to seek consultation, thus making blepharoplasty the surgical procedure of choice for both cosmetic and functional amelioration. The applied anatomy, indications of upper eyelid blepharoplasty, preoperative workup, surgical procedure, postoperative care, and complications would be discussed in detail in this review article.

  16. A comprehensive biogeochemical record and annual flux estimates for the Sabaki River (Kenya

    T. R. Marwick

    2018-03-01

    Full Text Available Inland waters impart considerable influence on nutrient cycling and budget estimates across local, regional and global scales, whilst anthropogenic pressures, such as rising populations and the appropriation of land and water resources, are undoubtedly modulating the flux of carbon (C, nitrogen (N and phosphorus (P between terrestrial biomes to inland waters, and the subsequent flux of these nutrients to the marine and atmospheric domains. Here, we present a 2-year biogeochemical record (October 2011–December 2013 at biweekly sampling resolution for the lower Sabaki River, Kenya, and provide estimates for suspended sediment and nutrient export fluxes from the lower Sabaki River under pre-dam conditions, and in light of the approved construction of the Thwake Multipurpose Dam on its upper reaches (Athi River. Erratic seasonal variation was typical for most parameters, with generally poor correlation between discharge and material concentrations, and stable isotope values of C (δ13C and N (δ15N. Although high total suspended matter (TSM concentrations are reported here (up to ∼ 3.8 g L−1, peak concentrations of TSM rarely coincided with peak discharge. The contribution of particulate organic C (POC to the TSM pool indicates a wide biannual variation in suspended sediment load from OC poor (0.3 % to OC rich (14.9 %, with the highest %POC occurring when discharge is < 100 m3 s−1 and at lower TSM concentrations. The consistent 15N enrichment of the particulate nitrogen (PN pool compared to other river systems indicates anthropogenic N loading is a year-round driver of N export from the Sabaki Basin. The lower Sabaki River was consistently oversaturated in dissolved methane (CH4; from 499 to 135 111 % and nitrous oxide (N2O; 100 to 463 % relative to atmospheric concentrations. Wet season flows (October–December and March–May carried > 80 % of the total load for TSM (∼ 86 %, POC (∼ 89 %, dissolved

  17. Climate of the upper atmosphere

    Christoph Jacobi

    2009-06-01

    Full Text Available

    In the frame of the European COST 296 project (Mitigation of Ionospheric Effects on Radio Systems, MIERS

    investigations of the climate of the upper atmosphere have been carried out during the last four years to obtain

    new information on the upper atmosphere. Mainly its ionospheric part has been analysed as the ionosphere

    most essential for the propagation of radio waves. Due to collaboration between different European partners

    many new results have been derived in the fields of long-term trends of different ionospheric and related atmospheric

    parameters, the investigations of different types of atmospheric waves and their impact on the ionosphere,

    the variability of the ionosphere, and the investigation of some space weather effects on the ionosphere.


  18. 234Th-based measurements of particle flux in surface water of the Bransfield Strait, western Antarctica

    Gulin, S.B.; National Academy of Sciences of Ukraine, Sevastopol, Autonomous Republic of Crimea

    2014-01-01

    Measurements of particulate and dissolved 234 Th were carried out in March 2002 in the Bransfield Strait located between the Antarctic Peninsula and the South Shetland Islands. The 234 Th/ 238 U disequilibrium found in the upper water column has allowed evaluation of downward particle fluxes across a frontal zone, which divides water masses coming from the Bellingshausen Sea and the Weddell Sea. The highest particle flux has been found in this mixing zone, where it was 3-5 times greater than in the adjacent waters. Total mass fluxes in the upper 150-m water column were estimated as about 2.2 g m -2 day -1 in the eastern part of the Strait and 3.1 g m -2 day -1 in the western area. (author)

  19. On the analytical flux distribution modeling of an axial-flux surface-mounted permanent magnet motor for control applications

    Liu, C.-T.; Lin, S.-C.; Chiang, T.-S.

    2004-01-01

    By combining the recoil line characteristics of permanent magnet and the equivalent operational magnetic circuits at various rotor positions, a systematic procedure for developing the desired analytical model of an axial-flux surface-mounted permanent magnet motor can be devised. Supported by detailed three-dimensional finite element analysis results and statistical evaluations, accuracies of the developed analytical model can be guaranteed. With such well developed system model, the relative high-precision controls and operations of the motor can then be conveniently realized

  20. Carbon stocks and fluxes in managed peatlands in northern Borneo

    Arn Teh, Yit; Manning, Frances; Cook, Sarah; Zin Zawawi, Norliyana; Sii, Longwin; Hill, Timothy; Page, Susan; Whelan, Mick; Evans, Chris; Gauci, Vincent; Chocholek, Melanie; Khoon Kho, Lip

    2017-04-01

    -1 yr-1, with 26 % accounted for by root-rhizosphere respiration and 74 % from heterotrophic soil respiration. This translates to a peat mineralization rate of 10 to 17 Mg C ha-1 yr-1 in the upper 35 cm soil depth above the water table. Fluvial C fluxes were 1.9 Mg C ha-1yr-1, or roughly three times the flux from secondary forest. Findings from the partitioned soil respiration and fluvial flux measurements indicate that peat mineralization may be occurring. However, it is unclear if this represents a net loss of C from the ecosystem, due to the apparent increase in soil C stocks following land conversion, rather than an expected net reduction in soil C. This unexpected finding implies that other processes may be offsetting C losses from heterotrophic decay and fluvial exchange.